45 files changed, 8599 insertions, 0 deletions
diff --git a/Android.mk b/Android.mk new file mode 100644 index 0000000..a2fbb48 --- a/dev/null +++ b/Android.mk @@ -0,0 +1,119 @@ +# +# Copyright 2016, The Android Open Source Project +# +# Permission is hereby granted, free of charge, to any person +# obtaining a copy of this software and associated documentation +# files (the "Software"), to deal in the Software without +# restriction, including without limitation the rights to use, copy, +# modify, merge, publish, distribute, sublicense, and/or sell copies +# of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be +# included in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# + +LOCAL_PATH := $(my-dir) + +avb_common_cflags := \ + -D_FILE_OFFSET_BITS=64 \ + -D_POSIX_C_SOURCE=199309L \ + -Wa,--noexecstack \ + -Werror \ + -Wall \ + -Wextra \ + -Wformat=2 \ + -Wno-psabi \ + -Wno-unused-parameter \ + -ffunction-sections \ + -fstack-protector-strong \ + -g +avb_common_cppflags := \ + -Wnon-virtual-dtor \ + -fno-strict-aliasing +avb_common_ldflags := \ + -Wl,--gc-sections \ + -rdynamic + +# Build libavb for the target (for e.g. fs_mgr usage). +include $(CLEAR_VARS) +LOCAL_MODULE := libavb_amlogic +LOCAL_MODULE_HOST_OS := linux +LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH) +LOCAL_CLANG := true +LOCAL_CFLAGS := $(avb_common_cflags) -DAVB_ENABLE_DEBUG -DAVB_COMPILATION +LOCAL_LDFLAGS := $(avb_common_ldflags) +LOCAL_SRC_FILES := \ + libavb/avb_chain_partition_descriptor.c \ + libavb/avb_crc32.c \ + libavb/avb_crypto.c \ + libavb/avb_descriptor.c \ + libavb/avb_footer.c \ + libavb/avb_hash_descriptor.c \ + libavb/avb_hashtree_descriptor.c \ + libavb/avb_kernel_cmdline_descriptor.c \ + libavb/avb_property_descriptor.c \ + libavb/avb_rsa.c \ + libavb/avb_sha256.c \ + libavb/avb_sha512.c \ + libavb/avb_slot_verify.c \ + libavb/avb_sysdeps_posix.c \ + libavb/avb_util.c \ + libavb/avb_vbmeta_image.c \ + libavb/avb_version.c +LOCAL_SHARED_LIBRARIES := liblog +include $(BUILD_STATIC_LIBRARY) + +# Build avbctl for the target. +include $(CLEAR_VARS) +LOCAL_MODULE := avbctl_amlogic +LOCAL_MODULE_CLASS := EXECUTABLES +LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH) +LOCAL_CPP_EXTENSION := .cc +LOCAL_CLANG := true +LOCAL_CFLAGS := $(avb_common_cflags) -DAVB_COMPILATION -DAVB_ENABLE_DEBUG +LOCAL_CPPFLAGS := $(avb_common_cppflags) +LOCAL_LDFLAGS := $(avb_common_ldflags) +LOCAL_STATIC_LIBRARIES := \ + libavb \ + libfs_mgr +LOCAL_SHARED_LIBRARIES := \ + libbase \ + libhidlbase \ + libhidltransport \ + libhwbinder \ + libutils \ + liblog \ + android.hardware.boot@1.0 +LOCAL_SRC_FILES := \ + libavb_ab/avb_ab_flow.c \ + libavb_user/avb_ops_user.c \ + tools/avbctl/avbctl.cc +include $(BUILD_EXECUTABLE) + +include $(CLEAR_VARS) +LOCAL_MODULE := bootctrl.amlogic +LOCAL_MODULE_RELATIVE_PATH := hw +LOCAL_REQUIRED_MODULES := libavb_amlogic +LOCAL_SRC_FILES := \ + libavb_ab/avb_ab_flow.c \ + libavb_user/avb_ops_user.c \ + boot_control/boot_control_avb.c +LOCAL_CLANG := true +LOCAL_CFLAGS := $(avb_common_cflags) -DAVB_COMPILATION -DAVB_ENABLE_DEBUG +LOCAL_LDFLAGS := $(avb_common_ldflags) +LOCAL_SHARED_LIBRARIES := libbase libcutils liblog +LOCAL_STATIC_LIBRARIES := libfs_mgr libavb +ifeq ($(shell test $(PLATFORM_SDK_VERSION) -ge 26 && echo OK),OK) +LOCAL_PROPRIETARY_MODULE := true +endif +include $(BUILD_SHARED_LIBRARY) diff --git a/README.md b/README.md new file mode 100755 index 0000000..89243af --- a/dev/null +++ b/README.md @@ -0,0 +1,346 @@ +#Amlogic 1.0 + +we copy it from external/avb +commit: 2afa76e8859a39cf0ef2b2f96ff092f6ee440a41 + +# Android Verified Boot 2.0 + +This repository contains tools and libraries for working with Android +Verified Boot 2.0. Usually AVB is used to refer to this codebase. + +## Introduction + +The main job of `avbtool` is to create `vbmeta.img` which is the +top-level object for verified boot. This image is designed to go into +the `vbmeta` partition (or, if using A/B, the slot in question +e.g. `vbmeta_a` or `vbmeta_b`) and be of minimal size (for out-of-band +updates). The vbmeta image is cryptographically signed and contains +verification data (e.g. cryptographic digests) for verifying +`boot.img`, `system.img`, and other partitions/images. + +The vbmeta image can also contain references to other partitions where +verification data is stored as well as a public key indicating who +should sign the verification data. This indirection provides +delegation, that is, it allows a 3rd party to control content on a +given partition by including their public key in `vbmeta.img`. By +design, this authority can be easily revoked by simply updating +`vbmeta.img` with new descriptors for the partition in question. + +Storing signed verification data on other images - for example +`boot.img` and `system.img` - is also done with `avbtool`. + +In addition to `avbtool`, a library - `libavb` - is provided. This +library performs all verification on the device side e.g. it starts by +loading the vbmeta partition, checks the signature, and then goes on +to load the boot partition for verification. This library is intended +to be used in both boot loaders and inside Android. It has a simple +abstraction for system dependencies (see `avb_sysdeps.h`) as well as +operations that the boot loader or OS is expected to implement (see +`avb_ops.h`). The main entry point for verification is +`avb_slot_verify()`. + +It is expected that most devices will use A/B (e.g. multiple copies of +the OS in separate so-called 'slots') in addition to AVB. While +managing A/B metadata and associated metadata (e.g. managing +`stored_rollback_index[n]` locations) is outside the scope of +`libavb`, enough interfaces are exposed so the boot loader can +integrate its A/B stack with `libavb`. In particular +`avb_slot_verify()` takes a `slot_suffix` parameter and its result +struct `AvbSlotVerifyData` convey the rollback indexes in the image +that was verified. + +AVB also includes an A/B implementation that boot loaders may +optionally use. This implementation is in the `libavb_ab` library and +integrates with image verification including updating the +`stored_rollback_index[n]` locations on the device as needed. The +bootloader can use this through the `avb_ab_flow()` function which in +turn calls `avb_slot_verify()` as needed. + +In `libavb_ab`, A/B metadata is stored in the `misc` partition using a +format private to `libavb_ab` in the location on `misc` reserved for +this. For more information about the `misc.img` file format see +the +[bootloader_message.h](https://android.googlesource.com/platform/bootable/recovery/+/master/bootloader_message/include/bootloader_message/bootloader_message.h) file +in AOSP. A/B metadata can be written to `misc.img` using the +`set_ab_metadata` sub-command of `avbtool`. A/B metadata is comprised +of data for each slo and per-slot metadata has a priority field (0 to +15), number of tries remaining for attempting to boot the slot (0 to +7), and a flag to indicate whether the slot has successfully booted. + +A/B metadata integrity is provided by a simple magic marker and a +CRC-32 checksum. If invalid A/B metadata is detected, the behavior is +to reset the A/B metadata to a known state where both slots are given +seven boot tries. + +An implementation of a boot_control HAL using AVB-specific A/B +metadata is also provided. + +Android Things has specific requirements and validation logic for the +vbmeta public key. An extension is provided in `libavb_atx` which +performs this validation as an implementatio of `libavb`'s public key +validation operation (see `avb_validate_vbmeta_public_key()` in +`avb_ops.h`). + +## Files and Directories + +* `libavb/` + + An implementation of image verification. This code is designed + to be highly portable so it can be used in as many contexts as + possible. This code requires a C99-compliant C compiler. Part of + this code is considered internal to the implementation and + should not be used outside it. For example, this applies to the + `avb_rsa.[ch]` and `avb_sha.[ch]` files. System dependencies + expected to be provided by the platform is defined in + `avb_sysdeps.h`. If the platform provides the standard C runtime + `avb_sysdeps_posix.c` can be used. +* `libavb_ab/` + + An A/B implementation for use in boot loaders. +* `libavb_atx/` + + An Android Things Extension for validating public key metadata. +* `libavb_user/` + + Contains an AvbOps implementation suitable for use in userspace + on the device (used in boot_control.avb and avbctl). +* `boot_control/` + + An implemementation of the Android boot_control HAL for use with + boot loaders using `libavb_ab`. +* `Android.mk` + + Build instructions for building libavb (a static library for use + on the device), host-side libraries (for unit tests), and unit + tests. +* `avbtool` + + A tool written in Python for working with images related to + verified boot. +* `test/` + + Unit tests for `abvtool`, `libavb`, `libavb_ab`, and + `libavb_atx`. +* `tools/avbctl/` + + Contains the source-code for a tool that can be used to control + AVB at runtime. +* `examples/uefi/` + + Contains the source-code for a UEFI-based boot-loader utilizing + `libavb/` and `libavb_ab/`. + +## Audience and portability notes + +This code is intended to be used in bootloaders in devices running +Android. The suggested approach is to copy the appropriate header and +C files mentioned in the previous section into the boot loader and +integrate as appropriate. + +The `libavb/` and `libavb_ab/` codebase will evolve over time so +integration should be as non-invasive as possible. The intention is to +keep the API of the library stable however it will be broken if +necessary. As for portability, the library is intended to be highly +portable, work on both little- and big-endian architectures and 32- +and 64-bit. It's also intended to work in non-standard environments +without the standard C library and runtime. + +If the `AVB_ENABLE_DEBUG` preprocessor symbol is set, the code will +include useful debug information and run-time checks. Production +builds should not use this. The preprocessor symbol `AVB_COMPILATION` +should be set only when compiling the libraries. The code must be +compiled into a separate libraries. + +Applications using the compiled `libavb` library must only include the +`libavb/libavb.h` file (which will include all public interfaces) and +must not have the `AVB_COMPILATION` preprocessor symbol set. This is +to ensure that internal code that may be change in the future (for +example `avb_sha.[ch]` and `avb_rsa.[ch]`) will not be visible to +application code. + +## Versioning and compatibility + +AVB uses a version number with three fields - the major, minor, and +sub version. Here's an example version number + + 1.4.3 + ^ ^ ^ + | | | + the major version ---+ | | + the minor version -----+ | + the sub version -------+ + +The major version number is bumped only if compatibility is broken, +e.g. a struct field has been removed or changed. The minor version +number is bumped only if a new feature is introduced, for example a +new algorithm or descriptor has been added. The sub version number is +bumped when bugs are fixed or other changes not affecting +compatibility are made. + +The `AvbVBMetaImageHeader` struct (as defined in the +`avb_vbmeta_image.h`) carries the major and minor version number of +`libavb` required to verify the struct in question. This is stored in +the `required_libavb_version_major` and +`required_libavb_version_minor` fields. Additionally this struct +contains a textual field with the version of `avbtool` used to create +the struct, for example "avbtool 1.4.3" or "avbtool 1.4.3 some_board +Git-4589fbec". + +Note that it's entirely possible to have a `AvbVBMetaImageHeader` +struct with + + required_libavb_version_major = 1 + required_libavb_version_minor = 0 + avbtool_release_string = "avbtool 1.4.3" + +if, for example, creating an image that does not use any features +added after AVB version 1.0. + +## Adding new features + +If adding a new feature for example a new algorithm or a new +descriptor then `AVB_VERSION_MINOR` in `avb_version.h` and `avbtool` +must be bumped and `AVB_VERSION_SUB` should be set to zero. + +Unit tests **MUST** be added to check that + +* The feature is used if - and only if - suitable commands/options are + passed to `avbtool`. +* The `required_version_minor` field is set to the bumped value if - + and only if - the feature is used. + +If `AVB_VERSION_MINOR` has already been bumped since the last release +there is obviously no need to bump it again. + +## Usage + +The content for the vbmeta partition can be generated as follows: + + $ avbtool make_vbmeta_image \ + --output OUTPUT \ + [--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \ + [--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \ + [--include_descriptors_from_footer /path/to/image.bin] \ + [--setup_rootfs_from_kernel /path/to/image.bin] \ + [--chain_partition part_name:rollback_index_location:/path/to/key1.bin] \ + [--signing_helper /path/to/external/signer] \ + [--append_to_release_string STR] + +An integrity footer containing the hash for an entire partition can be +added to an existing image as follows: + + $ avbtool add_hash_footer \ + --image IMAGE \ + --partition_name PARTNAME --partition_size SIZE \ + [--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \ + [--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \ + [--hash_algorithm HASH_ALG] [--salt HEX] \ + [--include_descriptors_from_footer /path/to/image.bin] \ + [--setup_rootfs_from_kernel /path/to/image.bin] \ + [--output_vbmeta_image OUTPUT_IMAGE] [--do_not_append_vbmeta_image] \ + [--signing_helper /path/to/external/signer] \ + [--append_to_release_string STR] + +An integrity footer containing the root digest and salt for a hashtree +for a partition can be added to an existing image as follows. The +hashtree is also appended to the image. + + $ avbtool add_hashtree_footer \ + --image IMAGE \ + --partition_name PARTNAME --partition_size SIZE \ + [--algorithm ALGORITHM] [--key /path/to/key_used_for_signing_or_pub_key] \ + [--public_key_metadata /path/to/pkmd.bin] [--rollback_index NUMBER] \ + [--hash_algorithm HASH_ALG] [--salt HEX] [--block_size SIZE] \ + [--include_descriptors_from_footer /path/to/image.bin] \ + [--setup_rootfs_from_kernel /path/to/image.bin] \ + [--output_vbmeta_image OUTPUT_IMAGE] [--do_not_append_vbmeta_image] \ + [--generate_fec] [--fec_num_roots FEC_NUM_ROOTS] \ + [--signing_helper /path/to/external/signer] \ + [--append_to_release_string STR] + +The integrity footer on an image can be removed from an image. The +hashtree can optionally be kept in place. + + $ avbtool erase_footer --image IMAGE [--keep_hashtree] + +For hash- and hashtree-images the vbmeta struct can also be written to +an external file via the `--output_vbmeta_image` option and one can +also specify that the vbmeta struct and footer not be added to the +image being operated on. + +To calculate the maximum size of an image that will fit in a partition +of a given size after having used the `avbtool add_hashtree_footer` +command on it, use the `--calc_max_image_size` option: + + $ avbtool add_hashtree_footer --partition_size $((10*1024*1024)) \ + --calc_max_image_size + 10330112 + +The `--signing_helper` option can be used in `make_vbmeta_image`, +`add_hash_footer` and `add_hashtree_footer` commands to specify any +external program for signing hashes. The data to sign (including +padding e.g. PKCS1-v1.5) is fed via `STDIN` and the signed data is +returned via `STDOUT`. If `--signing_helper` is present in a command +line, the `--key` option need only contain a public key. Arguments for +a signing helper are `algorithm` and `public key`. If the signing +helper exits with a non-zero exit code, it means failure. + +Here's an example invocation: + + /path/to/my_signing_program SHA256_RSA2048 /path/to/publickey.pem + +The `append_vbmeta_image` command can be used to append an entire +vbmeta blob to the end of another image. This is useful for cases when +not using any vbmeta partitions, for example: + + $ cp boot.img boot-with-vbmeta-appended.img + $ avbtool append_vbmeta_image \ + --image boot-with-vbmeta-appended.img \ + --partition_size SIZE_OF_BOOT_PARTITION \ + --vbmeta_image vbmeta.img + $ fastboot flash boot boot-with-vbmeta-appended.img + +## Build system integration notes + +Android Verified Boot is enabled by the `BOARD_AVB_ENABLE` variable + + BOARD_AVB_ENABLE := true + +This will make the build system create `vbmeta.img` which will contain +a hash descriptor for `boot.img`, a hashtree descriptor for +`system.img`, a kernel-cmdline descriptor for setting up `dm-verity` +for `system.img` and append a hash-tree to `system.img`. + +By default, the algorithm `SHA256_RSA4096` is used with a test key +from the `external/avb/test/data` directory. This can be overriden by +the `BOARD_AVB_ALGORITHM` and `BOARD_AVB_KEY_PATH` variables to use +e.g. a 4096-bit RSA key and SHA-512: + + BOARD_AVB_ALGORITHM := SHA512_RSA4096 + BOARD_AVB_KEY_PATH := /path/to/rsa_key_4096bits.pem + +Remember that the public part of this key needs to be available to the +bootloader of the device expected to verify resulting images. Use +`avbtool extract_public_key` to extract the key in the expected format +(**AVB_pk** in the following). If the device is using a different root +of trust than **AVB_pk** the `--public_key_metadata` option can be +used to embed a blob (**AVB_pkmd** in the following) that can be used +to e.g. derive **AVB_pk**. Both **AVB_pk** and **AVB_pkmd** are passed +to the `validate_vbmeta_public_key()` operation when verifying a slot. + +To prevent rollback attacks, the rollback index should be increased on +a regular basis. The rollback index can be set with the +`BOARD_AVB_ROLLBACK_INDEX` variable: + + BOARD_AVB_ROLLBACK_INDEX := 5 + +If this is not set, the rollback index defaults to 0. + +The variable `BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS` can be used to specify +additional options passed to `avbtool make_vbmeta_image`. Typical +options to be used here include `--prop`, `--prop_from_file`, and +`--chain_partition`. + +The variable `BOARD_AVBTOOL_BOOT_ADD_HASH_FOOTER_ARGS` can be used to +specify additional options passed to `avbtool add_hash_footer` for +`boot.img`. Typical options to be used here include `--hash_algorithm` +and `--salt`. + +The variable `BOARD_AVBTOOL_SYSTEM_ADD_HASHTREE_FOOTER_ARGS` can be +used to specify additional options passed to `avbtool +add_hashtree_footer` for `system.img`. Typical options to be used here +include `--hash_algorithm`, `--salt`, `--block_size`, and +`--generate_fec`. + +Build system variables (such as `PRODUCT_SUPPORTS_VERITY_FEC`) used +for previous version of Verified Boot in Android are not used in AVB diff --git a/boot_control/boot_control_avb.c b/boot_control/boot_control_avb.c new file mode 100644 index 0000000..aa439a7 --- a/dev/null +++ b/boot_control/boot_control_avb.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#define LOG_TAG "control_avb" + +#include <log/log.h> + +#include <errno.h> +#include <string.h> + +#include <cutils/properties.h> +#include <hardware/boot_control.h> +#include <hardware/hardware.h> + +#include <libavb_user/libavb_user.h> + +static AvbOps* ops = NULL; + +static void module_init(boot_control_module_t* module) { + if (ops != NULL) { + return; + } + + ops = avb_ops_user_new(); + if (ops == NULL) { + ALOGE("Unable to allocate AvbOps instance.\n"); + } +} + +static unsigned int module_getNumberSlots(boot_control_module_t* module) { + return 2; +} + +static unsigned int module_getCurrentSlot(boot_control_module_t* module) { + char propbuf[PROPERTY_VALUE_MAX]; + + property_get("ro.boot.slot_suffix", propbuf, ""); + + ALOGE("module_getCurrentSlot slot suffix: %s", propbuf); + + if (strcmp(propbuf, "_a") == 0) { + return 0; + } else if (strcmp(propbuf, "_b") == 0) { + return 1; + } else { + ALOGE("Unexpected slot suffix: %s", propbuf); + return 0; + } + return 0; +} + +static int module_markBootSuccessful(boot_control_module_t* module) { + AvbIOResult ret; + ret = avb_ab_mark_slot_successful(ops->ab_ops, module_getCurrentSlot(module)); + if (ret == AVB_IO_RESULT_OK) { + return 0; + } else if (ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION) { + return -1; + } else { + return -EIO; + } +} + +static int module_setActiveBootSlot(boot_control_module_t* module, + unsigned int slot) { + if (avb_ab_mark_slot_active(ops->ab_ops, slot) == AVB_IO_RESULT_OK) { + return 0; + } else { + return -EIO; + } +} + +static int module_setSlotAsUnbootable(struct boot_control_module* module, + unsigned int slot) { + if (avb_ab_mark_slot_unbootable(ops->ab_ops, slot) == AVB_IO_RESULT_OK) { + return 0; + } else { + return -EIO; + } +} + +static int module_isSlotBootable(struct boot_control_module* module, + unsigned int slot) { + AvbABData ab_data; + bool is_bootable; + if (slot >= 2) { + return -1; + } + + if (avb_ab_data_read(ops->ab_ops, &ab_data) != AVB_IO_RESULT_OK) { + return -EIO; + } + + is_bootable = (ab_data.slots[slot].priority > 0) && + (ab_data.slots[slot].successful_boot || + (ab_data.slots[slot].tries_remaining > 0)); + + return is_bootable ? 1 : 0; +} + +static int module_isSlotMarkedSuccessful(struct boot_control_module* module, + unsigned int slot) { + AvbABData ab_data; + bool is_marked_successful; + if (slot >= 2) { + return -1; + } + + if (avb_ab_data_read(ops->ab_ops, &ab_data) != AVB_IO_RESULT_OK) { + return -EIO; + } + + is_marked_successful = ab_data.slots[slot].successful_boot; + + return is_marked_successful ? 1 : 0; +} + +static const char* module_getSuffix(boot_control_module_t* module, + unsigned int slot) { + static const char* suffix[2] = {"_a", "_b"}; + if (slot >= 2) { + return NULL; + } + return suffix[slot]; +} + +static struct hw_module_methods_t module_methods = { + .open = NULL, +}; + +boot_control_module_t HAL_MODULE_INFO_SYM = { + .common = + { + .tag = HARDWARE_MODULE_TAG, + .module_api_version = BOOT_CONTROL_MODULE_API_VERSION_0_1, + .hal_api_version = HARDWARE_HAL_API_VERSION, + .id = BOOT_CONTROL_HARDWARE_MODULE_ID, + .name = "AVB implementation of boot_control HAL", + .author = "The Android Open Source Project", + .methods = &module_methods, + }, + .init = module_init, + .getNumberSlots = module_getNumberSlots, + .getCurrentSlot = module_getCurrentSlot, + .markBootSuccessful = module_markBootSuccessful, + .setActiveBootSlot = module_setActiveBootSlot, + .setSlotAsUnbootable = module_setSlotAsUnbootable, + .isSlotBootable = module_isSlotBootable, + .getSuffix = module_getSuffix, + .isSlotMarkedSuccessful = module_isSlotMarkedSuccessful, +}; diff --git a/libavb/avb_chain_partition_descriptor.c b/libavb/avb_chain_partition_descriptor.c new file mode 100644 index 0000000..3f14232 --- a/dev/null +++ b/libavb/avb_chain_partition_descriptor.c @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_chain_partition_descriptor.h" +#include "avb_util.h" + +bool avb_chain_partition_descriptor_validate_and_byteswap( + const AvbChainPartitionDescriptor* src, AvbChainPartitionDescriptor* dest) { + uint64_t expected_size; + + avb_memcpy(dest, src, sizeof(AvbChainPartitionDescriptor)); + + if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src, + (AvbDescriptor*)dest)) + return false; + + if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_CHAIN_PARTITION) { + avb_error("Invalid tag for chain partition descriptor.\n"); + return false; + } + + dest->rollback_index_location = avb_be32toh(dest->rollback_index_location); + dest->partition_name_len = avb_be32toh(dest->partition_name_len); + dest->public_key_len = avb_be32toh(dest->public_key_len); + + if (dest->rollback_index_location < 1) { + avb_error("Invalid rollback index location value.\n"); + return false; + } + + /* Check that partition_name and public_key are fully contained. */ + expected_size = sizeof(AvbChainPartitionDescriptor) - sizeof(AvbDescriptor); + if (!avb_safe_add_to(&expected_size, dest->partition_name_len) || + !avb_safe_add_to(&expected_size, dest->public_key_len)) { + avb_error("Overflow while adding up sizes.\n"); + return false; + } + if (expected_size > dest->parent_descriptor.num_bytes_following) { + avb_error("Descriptor payload size overflow.\n"); + return false; + } + return true; +} diff --git a/libavb/avb_chain_partition_descriptor.h b/libavb/avb_chain_partition_descriptor.h new file mode 100644 index 0000000..f2c9250 --- a/dev/null +++ b/libavb/avb_chain_partition_descriptor.h @@ -0,0 +1,72 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_CHAIN_PARTITION_DESCRIPTOR_H_ +#define AVB_CHAIN_PARTITION_DESCRIPTOR_H_ + +#include "avb_descriptor.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* A descriptor containing a pointer to signed integrity data stored + * on another partition. The descriptor contains the partition name in + * question (without the A/B suffix), the public key used to sign the + * integrity data, and rollback index location to use for rollback + * protection. + * + * Following this struct are |partition_name_len| bytes of the + * partition name (UTF-8 encoded) and |public_key_len| bytes of the + * public key. + * + * The |reserved| field is for future expansion and must be set to NUL + * bytes. + */ +typedef struct AvbChainPartitionDescriptor { + AvbDescriptor parent_descriptor; + uint32_t rollback_index_location; + uint32_t partition_name_len; + uint32_t public_key_len; + uint8_t reserved[64]; +} AVB_ATTR_PACKED AvbChainPartitionDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_chain_partition_descriptor_validate_and_byteswap( + const AvbChainPartitionDescriptor* src, + AvbChainPartitionDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_CHAIN_PARTITION_DESCRIPTOR_H_ */ diff --git a/libavb/avb_crc32.c b/libavb/avb_crc32.c new file mode 100644 index 0000000..9abed54 --- a/dev/null +++ b/libavb/avb_crc32.c @@ -0,0 +1,113 @@ +/*- + * COPYRIGHT (C) 1986 Gary S. Brown. You may use this program, or + * code or tables extracted from it, as desired without restriction. + */ + +/* + * First, the polynomial itself and its table of feedback terms. The + * polynomial is + * X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 + * + * Note that we take it "backwards" and put the highest-order term in + * the lowest-order bit. The X^32 term is "implied"; the LSB is the + * X^31 term, etc. The X^0 term (usually shown as "+1") results in + * the MSB being 1 + * + * Note that the usual hardware shift register implementation, which + * is what we're using (we're merely optimizing it by doing eight-bit + * chunks at a time) shifts bits into the lowest-order term. In our + * implementation, that means shifting towards the right. Why do we + * do it this way? Because the calculated CRC must be transmitted in + * order from highest-order term to lowest-order term. UARTs transmit + * characters in order from LSB to MSB. By storing the CRC this way + * we hand it to the UART in the order low-byte to high-byte; the UART + * sends each low-bit to hight-bit; and the result is transmission bit + * by bit from highest- to lowest-order term without requiring any bit + * shuffling on our part. Reception works similarly + * + * The feedback terms table consists of 256, 32-bit entries. Notes + * + * The table can be generated at runtime if desired; code to do so + * is shown later. It might not be obvious, but the feedback + * terms simply represent the results of eight shift/xor opera + * tions for all combinations of data and CRC register values + * + * The values must be right-shifted by eight bits by the "updcrc + * logic; the shift must be unsigned (bring in zeroes). On some + * hardware you could probably optimize the shift in assembler by + * using byte-swap instructions + * polynomial $edb88320 + * + * + * CRC32 code derived from work by Gary S. Brown. + */ + +#include "avb_sysdeps.h" + +/* Code taken from FreeBSD 8 */ + +static uint32_t crc32_tab[] = { + 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, + 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, + 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, + 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, + 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, + 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, + 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, + 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, + 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, + 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, + 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, + 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, + 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, + 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, + 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, + 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, + 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, + 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, + 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, + 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, + 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, + 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, + 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, + 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, + 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, + 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, + 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, + 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, + 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, + 0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, + 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28, + 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, + 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, + 0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, + 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242, + 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, + 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, + 0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, + 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, + 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, + 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, + 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, + 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d}; + +/* + * A function that calculates the CRC-32 based on the table above is + * given below for documentation purposes. An equivalent implementation + * of this function that's actually used in the kernel can be found + * in sys/libkern.h, where it can be inlined. + */ + +static uint32_t crc32(uint32_t crc_in, const uint8_t* buf, int size) { + const uint8_t* p = buf; + uint32_t crc; + + crc = crc_in ^ ~0U; + while (size--) + crc = crc32_tab[(crc ^ *p++) & 0xFF] ^ (crc >> 8); + return crc ^ ~0U; +} + +uint32_t avb_crc32(const uint8_t* buf, size_t size) { + return crc32(0, buf, size); +} diff --git a/libavb/avb_crypto.c b/libavb/avb_crypto.c new file mode 100644 index 0000000..a428443 --- a/dev/null +++ b/libavb/avb_crypto.c @@ -0,0 +1,373 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_crypto.h" +#include "avb_rsa.h" +#include "avb_sha.h" +#include "avb_util.h" + +/* NOTE: The PKC1-v1.5 padding is a blob of binary DER of ASN.1 and is + * obtained from section 5.2.2 of RFC 4880. + */ + +static const uint8_t + padding_RSA2048_SHA256[AVB_RSA2048_NUM_BYTES - AVB_SHA256_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0x00, 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, + 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20}; + +static const uint8_t + padding_RSA4096_SHA256[AVB_RSA4096_NUM_BYTES - AVB_SHA256_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, + 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20}; + +static const uint8_t + padding_RSA8192_SHA256[AVB_RSA8192_NUM_BYTES - AVB_SHA256_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0x00, 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, + 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20}; + +static const uint8_t + padding_RSA2048_SHA512[AVB_RSA2048_NUM_BYTES - AVB_SHA512_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, + 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40}; + +static const uint8_t + padding_RSA4096_SHA512[AVB_RSA4096_NUM_BYTES - AVB_SHA512_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x51, 0x30, + 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, + 0x05, 0x00, 0x04, 0x40}; + +static const uint8_t + padding_RSA8192_SHA512[AVB_RSA8192_NUM_BYTES - AVB_SHA512_DIGEST_SIZE] = { + 0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, + 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40}; + +static AvbAlgorithmData algorithm_data[_AVB_ALGORITHM_NUM_TYPES] = { + /* AVB_ALGORITHM_TYPE_NONE */ + {.padding = NULL, .padding_len = 0, .hash_len = 0}, + /* AVB_ALGORITHM_TYPE_SHA256_RSA2048 */ + {.padding = padding_RSA2048_SHA256, + .padding_len = sizeof(padding_RSA2048_SHA256), + .hash_len = AVB_SHA256_DIGEST_SIZE}, + /* AVB_ALGORITHM_TYPE_SHA256_RSA4096 */ + {.padding = padding_RSA4096_SHA256, + .padding_len = sizeof(padding_RSA4096_SHA256), + .hash_len = AVB_SHA256_DIGEST_SIZE}, + /* AVB_ALGORITHM_TYPE_SHA256_RSA8192 */ + {.padding = padding_RSA8192_SHA256, + .padding_len = sizeof(padding_RSA8192_SHA256), + .hash_len = AVB_SHA256_DIGEST_SIZE}, + /* AVB_ALGORITHM_TYPE_SHA512_RSA2048 */ + {.padding = padding_RSA2048_SHA512, + .padding_len = sizeof(padding_RSA2048_SHA512), + .hash_len = AVB_SHA512_DIGEST_SIZE}, + /* AVB_ALGORITHM_TYPE_SHA512_RSA4096 */ + {.padding = padding_RSA4096_SHA512, + .padding_len = sizeof(padding_RSA4096_SHA512), + .hash_len = AVB_SHA512_DIGEST_SIZE}, + /* AVB_ALGORITHM_TYPE_SHA512_RSA8192 */ + {.padding = padding_RSA8192_SHA512, + .padding_len = sizeof(padding_RSA8192_SHA512), + .hash_len = AVB_SHA512_DIGEST_SIZE}, +}; + +const AvbAlgorithmData* avb_get_algorithm_data(AvbAlgorithmType algorithm) { + if (algorithm >= AVB_ALGORITHM_TYPE_NONE && + algorithm < _AVB_ALGORITHM_NUM_TYPES) { + return &algorithm_data[algorithm]; + } + return NULL; +} + +bool avb_rsa_public_key_header_validate_and_byteswap( + const AvbRSAPublicKeyHeader* src, AvbRSAPublicKeyHeader* dest) { + avb_memcpy(dest, src, sizeof(AvbRSAPublicKeyHeader)); + + dest->key_num_bits = avb_be32toh(dest->key_num_bits); + dest->n0inv = avb_be32toh(dest->n0inv); + + return true; +} diff --git a/libavb/avb_crypto.h b/libavb/avb_crypto.h new file mode 100644 index 0000000..7e8d7e2 --- a/dev/null +++ b/libavb/avb_crypto.h @@ -0,0 +1,165 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_CRYPTO_H_ +#define AVB_CRYPTO_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Size of a RSA-2048 signature. */ +#define AVB_RSA2048_NUM_BYTES 256 + +/* Size of a RSA-4096 signature. */ +#define AVB_RSA4096_NUM_BYTES 512 + +/* Size of a RSA-8192 signature. */ +#define AVB_RSA8192_NUM_BYTES 1024 + +/* Size in bytes of a SHA-256 digest. */ +#define AVB_SHA256_DIGEST_SIZE 32 + +/* Size in bytes of a SHA-512 digest. */ +#define AVB_SHA512_DIGEST_SIZE 64 + +/* Algorithms that can be used in the vbmeta image for + * verification. An algorithm consists of a hash type and a signature + * type. + * + * The data used to calculate the hash is the three blocks mentioned + * in the documentation for |AvbVBMetaImageHeader| except for the data + * in the "Authentication data" block. + * + * For signatures with RSA keys, PKCS v1.5 padding is used. The public + * key data is stored in the auxiliary data block, see + * |AvbRSAPublicKeyHeader| for the serialization format. + * + * Each algorithm type is described below: + * + * AVB_ALGORITHM_TYPE_NONE: There is no hash, no signature of the + * data, and no public key. The data cannot be verified. The fields + * |hash_size|, |signature_size|, and |public_key_size| must be zero. + * + * AVB_ALGORITHM_TYPE_SHA256_RSA2048: The hash function used is + * SHA-256, resulting in 32 bytes of hash digest data. This hash is + * signed with a 2048-bit RSA key. The field |hash_size| must be 32, + * |signature_size| must be 256, and the public key data must have + * |key_num_bits| set to 2048. + * + * AVB_ALGORITHM_TYPE_SHA256_RSA4096: Like above, but only with + * a 4096-bit RSA key and |signature_size| set to 512. + * + * AVB_ALGORITHM_TYPE_SHA256_RSA8192: Like above, but only with + * a 8192-bit RSA key and |signature_size| set to 1024. + * + * AVB_ALGORITHM_TYPE_SHA512_RSA2048: The hash function used is + * SHA-512, resulting in 64 bytes of hash digest data. This hash is + * signed with a 2048-bit RSA key. The field |hash_size| must be 64, + * |signature_size| must be 256, and the public key data must have + * |key_num_bits| set to 2048. + * + * AVB_ALGORITHM_TYPE_SHA512_RSA4096: Like above, but only with + * a 4096-bit RSA key and |signature_size| set to 512. + * + * AVB_ALGORITHM_TYPE_SHA512_RSA8192: Like above, but only with + * a 8192-bit RSA key and |signature_size| set to 1024. + */ +typedef enum { + AVB_ALGORITHM_TYPE_NONE, + AVB_ALGORITHM_TYPE_SHA256_RSA2048, + AVB_ALGORITHM_TYPE_SHA256_RSA4096, + AVB_ALGORITHM_TYPE_SHA256_RSA8192, + AVB_ALGORITHM_TYPE_SHA512_RSA2048, + AVB_ALGORITHM_TYPE_SHA512_RSA4096, + AVB_ALGORITHM_TYPE_SHA512_RSA8192, + _AVB_ALGORITHM_NUM_TYPES +} AvbAlgorithmType; + +/* Holds algorithm-specific data. The |padding| is needed by avb_rsa_verify. */ +typedef struct { + const uint8_t* padding; + size_t padding_len; + size_t hash_len; +} AvbAlgorithmData; + +/* Provides algorithm-specific data for a given |algorithm|. Returns NULL if + * |algorithm| is invalid. + */ +const AvbAlgorithmData* avb_get_algorithm_data(AvbAlgorithmType algorithm) + AVB_ATTR_WARN_UNUSED_RESULT; + +/* The header for a serialized RSA public key. + * + * The size of the key is given by |key_num_bits|, for example 2048 + * for a RSA-2048 key. By definition, a RSA public key is the pair (n, + * e) where |n| is the modulus (which can be represented in + * |key_num_bits| bits) and |e| is the public exponent. The exponent + * is not stored since it's assumed to always be 65537. + * + * To optimize verification, the key block includes two precomputed + * values, |n0inv| (fits in 32 bits) and |rr| and can always be + * represented in |key_num_bits|. + + * The value |n0inv| is the value -1/n[0] (mod 2^32). The value |rr| + * is (2^key_num_bits)^2 (mod n). + * + * Following this header is |key_num_bits| bits of |n|, then + * |key_num_bits| bits of |rr|. Both values are stored with most + * significant bit first. Each serialized number takes up + * |key_num_bits|/8 bytes. + * + * All fields in this struct are stored in network byte order when + * serialized. To generate a copy with fields swapped to native byte + * order, use the function avb_rsa_public_key_header_validate_and_byteswap(). + * + * The avb_rsa_verify() function expects a key in this serialized + * format. + * + * The 'avbtool extract_public_key' command can be used to generate a + * serialized RSA public key. + */ +typedef struct AvbRSAPublicKeyHeader { + uint32_t key_num_bits; + uint32_t n0inv; +} AVB_ATTR_PACKED AvbRSAPublicKeyHeader; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + */ +bool avb_rsa_public_key_header_validate_and_byteswap( + const AvbRSAPublicKeyHeader* src, + AvbRSAPublicKeyHeader* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_CRYPTO_H_ */ diff --git a/libavb/avb_descriptor.c b/libavb/avb_descriptor.c new file mode 100644 index 0000000..4f8e925 --- a/dev/null +++ b/libavb/avb_descriptor.c @@ -0,0 +1,160 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_descriptor.h" +#include "avb_util.h" +#include "avb_vbmeta_image.h" + +bool avb_descriptor_validate_and_byteswap(const AvbDescriptor* src, + AvbDescriptor* dest) { + dest->tag = avb_be64toh(src->tag); + dest->num_bytes_following = avb_be64toh(src->num_bytes_following); + + if ((dest->num_bytes_following & 0x07) != 0) { + avb_error("Descriptor size is not divisible by 8.\n"); + return false; + } + return true; +} + +bool avb_descriptor_foreach(const uint8_t* image_data, + size_t image_size, + AvbDescriptorForeachFunc foreach_func, + void* user_data) { + const AvbVBMetaImageHeader* header = NULL; + bool ret = false; + const uint8_t* image_end; + const uint8_t* desc_start; + const uint8_t* desc_end; + const uint8_t* p; + + if (image_data == NULL) { + avb_error("image_data is NULL\n."); + goto out; + } + + if (foreach_func == NULL) { + avb_error("foreach_func is NULL\n."); + goto out; + } + + if (image_size < sizeof(AvbVBMetaImageHeader)) { + avb_error("Length is smaller than header.\n"); + goto out; + } + + /* Ensure magic is correct. */ + if (avb_memcmp(image_data, AVB_MAGIC, AVB_MAGIC_LEN) != 0) { + avb_error("Magic is incorrect.\n"); + goto out; + } + + /* Careful, not byteswapped - also ensure it's aligned properly. */ + avb_assert_aligned(image_data); + header = (const AvbVBMetaImageHeader*)image_data; + image_end = image_data + image_size; + + desc_start = image_data + sizeof(AvbVBMetaImageHeader) + + avb_be64toh(header->authentication_data_block_size) + + avb_be64toh(header->descriptors_offset); + + desc_end = desc_start + avb_be64toh(header->descriptors_size); + + if (desc_start < image_data || desc_start > image_end || + desc_end < image_data || desc_end > image_end || desc_end < desc_start) { + avb_error("Descriptors not inside passed-in data.\n"); + goto out; + } + + for (p = desc_start; p < desc_end;) { + const AvbDescriptor* dh = (const AvbDescriptor*)p; + avb_assert_aligned(dh); + uint64_t nb_following = avb_be64toh(dh->num_bytes_following); + uint64_t nb_total = sizeof(AvbDescriptor) + nb_following; + + if ((nb_total & 7) != 0) { + avb_error("Invalid descriptor length.\n"); + goto out; + } + + if (nb_total + p < desc_start || nb_total + p > desc_end) { + avb_error("Invalid data in descriptors array.\n"); + goto out; + } + + if (foreach_func(dh, user_data) == 0) { + goto out; + } + + p += nb_total; + } + + ret = true; + +out: + return ret; +} + +static bool count_descriptors(const AvbDescriptor* descriptor, + void* user_data) { + size_t* num_descriptors = user_data; + *num_descriptors += 1; + return true; +} + +typedef struct { + size_t descriptor_number; + const AvbDescriptor** descriptors; +} SetDescriptorData; + +static bool set_descriptors(const AvbDescriptor* descriptor, void* user_data) { + SetDescriptorData* data = user_data; + data->descriptors[data->descriptor_number++] = descriptor; + return true; +} + +const AvbDescriptor** avb_descriptor_get_all(const uint8_t* image_data, + size_t image_size, + size_t* out_num_descriptors) { + size_t num_descriptors = 0; + SetDescriptorData data; + + avb_descriptor_foreach( + image_data, image_size, count_descriptors, &num_descriptors); + + data.descriptor_number = 0; + data.descriptors = + avb_calloc(sizeof(const AvbDescriptor*) * (num_descriptors + 1)); + if (data.descriptors == NULL) { + return NULL; + } + avb_descriptor_foreach(image_data, image_size, set_descriptors, &data); + avb_assert(data.descriptor_number == num_descriptors); + + if (out_num_descriptors != NULL) { + *out_num_descriptors = num_descriptors; + } + + return data.descriptors; +} diff --git a/libavb/avb_descriptor.h b/libavb/avb_descriptor.h new file mode 100644 index 0000000..5d0f0c6 --- a/dev/null +++ b/libavb/avb_descriptor.h @@ -0,0 +1,131 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_DESCRIPTOR_H_ +#define AVB_DESCRIPTOR_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Well-known descriptor tags. + * + * AVB_DESCRIPTOR_TAG_PROPERTY: see |AvbPropertyDescriptor| struct. + * AVB_DESCRIPTOR_TAG_HASHTREE: see |AvbHashtreeDescriptor| struct. + * AVB_DESCRIPTOR_TAG_HASH: see |AvbHashDescriptor| struct. + * AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: see |AvbKernelCmdlineDescriptor| struct. + * AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: see |AvbChainPartitionDescriptor| struct. + */ +typedef enum { + AVB_DESCRIPTOR_TAG_PROPERTY, + AVB_DESCRIPTOR_TAG_HASHTREE, + AVB_DESCRIPTOR_TAG_HASH, + AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE, + AVB_DESCRIPTOR_TAG_CHAIN_PARTITION, +} AvbDescriptorTag; + +/* The header for a serialized descriptor. + * + * A descriptor always have two fields, a |tag| (denoting its type, + * see the |AvbDescriptorTag| enumeration) and the size of the bytes + * following, |num_bytes_following|. + * + * For padding, |num_bytes_following| is always a multiple of 8. + */ +typedef struct AvbDescriptor { + uint64_t tag; + uint64_t num_bytes_following; +} AVB_ATTR_PACKED AvbDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_descriptor_validate_and_byteswap( + const AvbDescriptor* src, AvbDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Signature for callback function used in avb_descriptor_foreach(). + * The passed in descriptor is given by |descriptor| and the + * |user_data| passed to avb_descriptor_foreach() function is in + * |user_data|. Return true to continue iterating, false to stop + * iterating. + * + * Note that |descriptor| points into the image passed to + * avb_descriptor_foreach() - all fields need to be byteswapped! + */ +typedef bool AvbDescriptorForeachFunc(const AvbDescriptor* descriptor, + void* user_data); + +/* Convenience function to iterate over all descriptors in an vbmeta + * image. + * + * The function given by |foreach_func| will be called for each + * descriptor. The given function should return true to continue + * iterating, false to stop. + * + * The |user_data| parameter will be passed to |foreach_func|. + * + * Returns false if the iteration was short-circuited, that is if + * an invocation of |foreach_func| returned false. + * + * Before using this function, you MUST verify |image_data| with + * avb_vbmeta_image_verify() and reject it unless it's signed by a known + * good public key. Additionally, |image_data| must be word-aligned. + */ +bool avb_descriptor_foreach(const uint8_t* image_data, + size_t image_size, + AvbDescriptorForeachFunc foreach_func, + void* user_data); + +/* Gets all descriptors in a vbmeta image. + * + * The return value is a NULL-pointer terminated array of + * AvbDescriptor pointers. Free with avb_free() when you are done with + * it. If |out_num_descriptors| is non-NULL, the number of descriptors + * will be returned there. + * + * Note that each AvbDescriptor pointer in the array points into + * |image_data| - all fields need to be byteswapped! + * + * Before using this function, you MUST verify |image_data| with + * avb_vbmeta_image_verify() and reject it unless it's signed by a known + * good public key. Additionally, |image_data| must be word-aligned. + */ +const AvbDescriptor** avb_descriptor_get_all(const uint8_t* image_data, + size_t image_size, + size_t* out_num_descriptors) + AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_DESCRIPTOR_H_ */ diff --git a/libavb/avb_footer.c b/libavb/avb_footer.c new file mode 100644 index 0000000..b8b8211 --- a/dev/null +++ b/libavb/avb_footer.c @@ -0,0 +1,54 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_footer.h" +#include "avb_util.h" + +bool avb_footer_validate_and_byteswap(const AvbFooter* src, AvbFooter* dest) { + avb_memcpy(dest, src, sizeof(AvbFooter)); + + dest->version_major = avb_be32toh(dest->version_major); + dest->version_minor = avb_be32toh(dest->version_minor); + + dest->original_image_size = avb_be64toh(dest->original_image_size); + dest->vbmeta_offset = avb_be64toh(dest->vbmeta_offset); + dest->vbmeta_size = avb_be64toh(dest->vbmeta_size); + + /* Check that magic is correct. */ + if (avb_safe_memcmp(dest->magic, AVB_FOOTER_MAGIC, AVB_FOOTER_MAGIC_LEN) != + 0) { + avb_error("Footer magic is incorrect.\n"); + return false; + } + + /* Ensure we don't attempt to access any fields if the footer major + * version is not supported. + */ + if (dest->version_major > AVB_FOOTER_VERSION_MAJOR) { + avb_error("No support for footer version.\n"); + return false; + } + + return true; +} diff --git a/libavb/avb_footer.h b/libavb/avb_footer.h new file mode 100644 index 0000000..e84826f --- a/dev/null +++ b/libavb/avb_footer.h @@ -0,0 +1,86 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_FOOTER_H_ +#define AVB_FOOTER_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Magic for the footer. */ +#define AVB_FOOTER_MAGIC "AVBf" +#define AVB_FOOTER_MAGIC_LEN 4 + +/* Size of the footer. */ +#define AVB_FOOTER_SIZE 64 + +/* The current footer version used - keep in sync with avbtool. */ +#define AVB_FOOTER_VERSION_MAJOR 1 +#define AVB_FOOTER_VERSION_MINOR 0 + +/* The struct used as a footer used on partitions, used to find the + * AvbVBMetaImageHeader struct. This struct is always stored at the + * end of a partition. + */ +typedef struct AvbFooter { + /* 0: Four bytes equal to "AVBf" (AVB_FOOTER_MAGIC). */ + uint8_t magic[AVB_FOOTER_MAGIC_LEN]; + /* 4: The major version of the footer struct. */ + uint32_t version_major; + /* 8: The minor version of the footer struct. */ + uint32_t version_minor; + + /* 12: The original size of the image on the partition. */ + uint64_t original_image_size; + + /* 20: The offset of the |AvbVBMetaImageHeader| struct. */ + uint64_t vbmeta_offset; + + /* 28: The size of the vbmeta block (header + auth + aux blocks). */ + uint64_t vbmeta_size; + + /* 36: Padding to ensure struct is size AVB_FOOTER_SIZE bytes. This + * must be set to zeroes. + */ + uint8_t reserved[28]; +} AVB_ATTR_PACKED AvbFooter; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + */ +bool avb_footer_validate_and_byteswap(const AvbFooter* src, AvbFooter* dest) + AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_FOOTER_H_ */ diff --git a/libavb/avb_hash_descriptor.c b/libavb/avb_hash_descriptor.c new file mode 100644 index 0000000..2e427de --- a/dev/null +++ b/libavb/avb_hash_descriptor.c @@ -0,0 +1,61 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_hash_descriptor.h" +#include "avb_util.h" + +bool avb_hash_descriptor_validate_and_byteswap(const AvbHashDescriptor* src, + AvbHashDescriptor* dest) { + uint64_t expected_size; + + avb_memcpy(dest, src, sizeof(AvbHashDescriptor)); + + if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src, + (AvbDescriptor*)dest)) + return false; + + if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_HASH) { + avb_error("Invalid tag for hash descriptor.\n"); + return false; + } + + dest->image_size = avb_be64toh(dest->image_size); + dest->partition_name_len = avb_be32toh(dest->partition_name_len); + dest->salt_len = avb_be32toh(dest->salt_len); + dest->digest_len = avb_be32toh(dest->digest_len); + + /* Check that partition_name, salt, and digest are fully contained. */ + expected_size = sizeof(AvbHashDescriptor) - sizeof(AvbDescriptor); + if (!avb_safe_add_to(&expected_size, dest->partition_name_len) || + !avb_safe_add_to(&expected_size, dest->salt_len) || + !avb_safe_add_to(&expected_size, dest->digest_len)) { + avb_error("Overflow while adding up sizes.\n"); + return false; + } + if (expected_size > dest->parent_descriptor.num_bytes_following) { + avb_error("Descriptor payload size overflow.\n"); + return false; + } + return true; +} diff --git a/libavb/avb_hash_descriptor.h b/libavb/avb_hash_descriptor.h new file mode 100644 index 0000000..2668118 --- a/dev/null +++ b/libavb/avb_hash_descriptor.h @@ -0,0 +1,73 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_HASH_DESCRIPTOR_H_ +#define AVB_HASH_DESCRIPTOR_H_ + +#include "avb_descriptor.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* A descriptor containing information about hash for an image. + * + * This descriptor is typically used for boot partitions to verify the + * entire kernel+initramfs image before executing it. + * + * Following this struct are |partition_name_len| bytes of the + * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then + * |digest_len| bytes of the digest. + * + * The |reserved| field is for future expansion and must be set to NUL + * bytes. + */ +typedef struct AvbHashDescriptor { + AvbDescriptor parent_descriptor; + uint64_t image_size; + uint8_t hash_algorithm[32]; + uint32_t partition_name_len; + uint32_t salt_len; + uint32_t digest_len; + uint8_t reserved[64]; +} AVB_ATTR_PACKED AvbHashDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_hash_descriptor_validate_and_byteswap(const AvbHashDescriptor* src, + AvbHashDescriptor* dest) + AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_HASH_DESCRIPTOR_H_ */ diff --git a/libavb/avb_hashtree_descriptor.c b/libavb/avb_hashtree_descriptor.c new file mode 100644 index 0000000..b961e47 --- a/dev/null +++ b/libavb/avb_hashtree_descriptor.c @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_hashtree_descriptor.h" +#include "avb_util.h" + +bool avb_hashtree_descriptor_validate_and_byteswap( + const AvbHashtreeDescriptor* src, AvbHashtreeDescriptor* dest) { + uint64_t expected_size; + + avb_memcpy(dest, src, sizeof(AvbHashtreeDescriptor)); + + if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src, + (AvbDescriptor*)dest)) + return false; + + if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_HASHTREE) { + avb_error("Invalid tag for hashtree descriptor.\n"); + return false; + } + + dest->dm_verity_version = avb_be32toh(dest->dm_verity_version); + dest->image_size = avb_be64toh(dest->image_size); + dest->tree_offset = avb_be64toh(dest->tree_offset); + dest->tree_size = avb_be64toh(dest->tree_size); + dest->data_block_size = avb_be32toh(dest->data_block_size); + dest->hash_block_size = avb_be32toh(dest->hash_block_size); + dest->fec_num_roots = avb_be32toh(dest->fec_num_roots); + dest->fec_offset = avb_be64toh(dest->fec_offset); + dest->fec_size = avb_be64toh(dest->fec_size); + dest->partition_name_len = avb_be32toh(dest->partition_name_len); + dest->salt_len = avb_be32toh(dest->salt_len); + dest->root_digest_len = avb_be32toh(dest->root_digest_len); + + /* Check that partition_name, salt, and root_digest are fully contained. */ + expected_size = sizeof(AvbHashtreeDescriptor) - sizeof(AvbDescriptor); + if (!avb_safe_add_to(&expected_size, dest->partition_name_len) || + !avb_safe_add_to(&expected_size, dest->salt_len) || + !avb_safe_add_to(&expected_size, dest->root_digest_len)) { + avb_error("Overflow while adding up sizes.\n"); + return false; + } + if (expected_size > dest->parent_descriptor.num_bytes_following) { + avb_error("Descriptor payload size overflow.\n"); + return false; + } + return true; +} diff --git a/libavb/avb_hashtree_descriptor.h b/libavb/avb_hashtree_descriptor.h new file mode 100644 index 0000000..a5aafbf --- a/dev/null +++ b/libavb/avb_hashtree_descriptor.h @@ -0,0 +1,83 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_HASHTREE_DESCRIPTOR_H_ +#define AVB_HASHTREE_DESCRIPTOR_H_ + +#include "avb_descriptor.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* A descriptor containing information about a dm-verity hashtree. + * + * Hash-trees are used to verify large partitions typically containing + * file systems. See + * https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for more + * information about dm-verity. + * + * Following this struct are |partition_name_len| bytes of the + * partition name (UTF-8 encoded), |salt_len| bytes of salt, and then + * |root_digest_len| bytes of the root digest. + * + * The |reserved| field is for future expansion and must be set to NUL + * bytes. + */ +typedef struct AvbHashtreeDescriptor { + AvbDescriptor parent_descriptor; + uint32_t dm_verity_version; + uint64_t image_size; + uint64_t tree_offset; + uint64_t tree_size; + uint32_t data_block_size; + uint32_t hash_block_size; + uint32_t fec_num_roots; + uint64_t fec_offset; + uint64_t fec_size; + uint8_t hash_algorithm[32]; + uint32_t partition_name_len; + uint32_t salt_len; + uint32_t root_digest_len; + uint8_t reserved[64]; +} AVB_ATTR_PACKED AvbHashtreeDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_hashtree_descriptor_validate_and_byteswap( + const AvbHashtreeDescriptor* src, + AvbHashtreeDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_HASHTREE_DESCRIPTOR_H_ */ diff --git a/libavb/avb_kernel_cmdline_descriptor.c b/libavb/avb_kernel_cmdline_descriptor.c new file mode 100644 index 0000000..67521f2 --- a/dev/null +++ b/libavb/avb_kernel_cmdline_descriptor.c @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_kernel_cmdline_descriptor.h" +#include "avb_util.h" + +bool avb_kernel_cmdline_descriptor_validate_and_byteswap( + const AvbKernelCmdlineDescriptor* src, AvbKernelCmdlineDescriptor* dest) { + uint64_t expected_size; + + avb_memcpy(dest, src, sizeof(AvbKernelCmdlineDescriptor)); + + if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src, + (AvbDescriptor*)dest)) + return false; + + if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE) { + avb_error("Invalid tag for kernel cmdline descriptor.\n"); + return false; + } + + dest->flags = avb_be32toh(dest->flags); + dest->kernel_cmdline_length = avb_be32toh(dest->kernel_cmdline_length); + + /* Check that kernel_cmdline is fully contained. */ + expected_size = sizeof(AvbKernelCmdlineDescriptor) - sizeof(AvbDescriptor); + if (!avb_safe_add_to(&expected_size, dest->kernel_cmdline_length)) { + avb_error("Overflow while adding up sizes.\n"); + return false; + } + if (expected_size > dest->parent_descriptor.num_bytes_following) { + avb_error("Descriptor payload size overflow.\n"); + return false; + } + + return true; +} diff --git a/libavb/avb_kernel_cmdline_descriptor.h b/libavb/avb_kernel_cmdline_descriptor.h new file mode 100644 index 0000000..6908b3b --- a/dev/null +++ b/libavb/avb_kernel_cmdline_descriptor.h @@ -0,0 +1,81 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_KERNEL_CMDLINE_DESCRIPTOR_H_ +#define AVB_KERNEL_CMDLINE_DESCRIPTOR_H_ + +#include "avb_descriptor.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Flags for kernel command-line descriptors. + * + * AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED: The + * cmdline will only be applied if hashtree verification is not + * disabled (cf. AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED). + * + * AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED: The cmdline + * will only be applied if hashtree verification is disabled + * (cf. AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED). + */ +typedef enum { + AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED = (1 << 0), + AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED = (1 << 1) +} AvbKernelCmdlineFlags; + +/* A descriptor containing information to be appended to the kernel + * command-line. + * + * The |flags| field contains flags from the AvbKernelCmdlineFlags + * enumeration. + * + * Following this struct are |kernel_cmdline_len| bytes with the + * kernel command-line (UTF-8 encoded). + */ +typedef struct AvbKernelCmdlineDescriptor { + AvbDescriptor parent_descriptor; + uint32_t flags; + uint32_t kernel_cmdline_length; +} AVB_ATTR_PACKED AvbKernelCmdlineDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_kernel_cmdline_descriptor_validate_and_byteswap( + const AvbKernelCmdlineDescriptor* src, + AvbKernelCmdlineDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_KERNEL_CMDLINE_DESCRIPTOR_H_ */ diff --git a/libavb/avb_ops.h b/libavb/avb_ops.h new file mode 100644 index 0000000..908c66c --- a/dev/null +++ b/libavb/avb_ops.h @@ -0,0 +1,214 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_OPS_H_ +#define AVB_OPS_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Return codes used for I/O operations. + * + * AVB_IO_RESULT_OK is returned if the requested operation was + * successful. + * + * AVB_IO_RESULT_ERROR_IO is returned if the underlying hardware (disk + * or other subsystem) encountered an I/O error. + * + * AVB_IO_RESULT_ERROR_OOM is returned if unable to allocate memory. + * + * AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION is returned if the requested + * partition does not exist. + * + * AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION is returned if the + * range of bytes requested to be read or written is outside the range + * of the partition. + */ +typedef enum { + AVB_IO_RESULT_OK, + AVB_IO_RESULT_ERROR_OOM, + AVB_IO_RESULT_ERROR_IO, + AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION, + AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION +} AvbIOResult; + +struct AvbOps; +typedef struct AvbOps AvbOps; + +/* Forward-declaration of operations in libavb_ab. */ +struct AvbABOps; + +/* Forward-declaration of operations in libavb_atx. */ +struct AvbAtxOps; + +/* High-level operations/functions/methods that are platform + * dependent. + */ +struct AvbOps { + /* This pointer can be used by the application/bootloader using + * libavb and is typically used in each operation to get a pointer + * to platform-specific resources. It cannot be used by libraries. + */ + void* user_data; + + /* If libavb_ab is used, this should point to the + * AvbABOps. Otherwise it must be set to NULL. + */ + struct AvbABOps* ab_ops; + + /* If libavb_atx is used, this should point to the + * AvbAtxOps. Otherwise it must be set to NULL. + */ + struct AvbAtxOps* atx_ops; + + /* Reads |num_bytes| from offset |offset| from partition with name + * |partition| (NUL-terminated UTF-8 string). If |offset| is + * negative, its absolute value should be interpreted as the number + * of bytes from the end of the partition. + * + * This function returns AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION if + * there is no partition with the given name, + * AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION if the requested + * |offset| is outside the partition, and AVB_IO_RESULT_ERROR_IO if + * there was an I/O error from the underlying I/O subsystem. If the + * operation succeeds as requested AVB_IO_RESULT_OK is returned and + * the data is available in |buffer|. + * + * The only time partial I/O may occur is if reading beyond the end + * of the partition. In this case the value returned in + * |out_num_read| may be smaller than |num_bytes|. + */ + AvbIOResult (*read_from_partition)(AvbOps* ops, + const char* partition, + int64_t offset, + size_t num_bytes, + void* buffer, + size_t* out_num_read); + + /* Writes |num_bytes| from |bffer| at offset |offset| to partition + * with name |partition| (NUL-terminated UTF-8 string). If |offset| + * is negative, its absolute value should be interpreted as the + * number of bytes from the end of the partition. + * + * This function returns AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION if + * there is no partition with the given name, + * AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION if the requested + * byterange goes outside the partition, and AVB_IO_RESULT_ERROR_IO + * if there was an I/O error from the underlying I/O subsystem. If + * the operation succeeds as requested AVB_IO_RESULT_OK is + * returned. + * + * This function never does any partial I/O, it either transfers all + * of the requested bytes or returns an error. + */ + AvbIOResult (*write_to_partition)(AvbOps* ops, + const char* partition, + int64_t offset, + size_t num_bytes, + const void* buffer); + + /* Checks if the given public key used to sign the 'vbmeta' + * partition is trusted. Boot loaders typically compare this with + * embedded key material generated with 'avbtool + * extract_public_key'. + * + * The public key is in the array pointed to by |public_key_data| + * and is of |public_key_length| bytes. + * + * If there is no public key metadata (set with the avbtool option + * --public_key_metadata) then |public_key_metadata| will be set to + * NULL. Otherwise this field points to the data which is + * |public_key_metadata_length| bytes long. + * + * If AVB_IO_RESULT_OK is returned then |out_is_trusted| is set - + * true if trusted or false if untrusted. + */ + AvbIOResult (*validate_vbmeta_public_key)(AvbOps* ops, + const uint8_t* public_key_data, + size_t public_key_length, + const uint8_t* public_key_metadata, + size_t public_key_metadata_length, + bool* out_is_trusted); + + /* Gets the rollback index corresponding to the location given by + * |rollback_index_location|. The value is returned in + * |out_rollback_index|. Returns AVB_IO_RESULT_OK if the rollback + * index was retrieved, otherwise an error code. + * + * A device may have a limited amount of rollback index locations (say, + * one or four) so may error out if |rollback_index_location| exceeds + * this number. + */ + AvbIOResult (*read_rollback_index)(AvbOps* ops, + size_t rollback_index_location, + uint64_t* out_rollback_index); + + /* Sets the rollback index corresponding to the location given by + * |rollback_index_location| to |rollback_index|. Returns + * AVB_IO_RESULT_OK if the rollback index was set, otherwise an + * error code. + * + * A device may have a limited amount of rollback index locations (say, + * one or four) so may error out if |rollback_index_location| exceeds + * this number. + */ + AvbIOResult (*write_rollback_index)(AvbOps* ops, + size_t rollback_index_location, + uint64_t rollback_index); + + /* Gets whether the device is unlocked. The value is returned in + * |out_is_unlocked| (true if unlocked, false otherwise). Returns + * AVB_IO_RESULT_OK if the state was retrieved, otherwise an error + * code. + */ + AvbIOResult (*read_is_device_unlocked)(AvbOps* ops, bool* out_is_unlocked); + + /* Gets the unique partition GUID for a partition with name in + * |partition| (NUL-terminated UTF-8 string). The GUID is copied as + * a string into |guid_buf| of size |guid_buf_size| and will be NUL + * terminated. The string must be lower-case and properly + * hyphenated. For example: + * + * 527c1c6d-6361-4593-8842-3c78fcd39219 + * + * Returns AVB_IO_RESULT_OK on success, otherwise an error code. + */ + AvbIOResult (*get_unique_guid_for_partition)(AvbOps* ops, + const char* partition, + char* guid_buf, + size_t guid_buf_size); +}; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_OPS_H_ */ diff --git a/libavb/avb_property_descriptor.c b/libavb/avb_property_descriptor.c new file mode 100644 index 0000000..7eba2c0 --- a/dev/null +++ b/libavb/avb_property_descriptor.c @@ -0,0 +1,185 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_property_descriptor.h" +#include "avb_util.h" + +bool avb_property_descriptor_validate_and_byteswap( + const AvbPropertyDescriptor* src, AvbPropertyDescriptor* dest) { + uint64_t expected_size; + + avb_memcpy(dest, src, sizeof(AvbPropertyDescriptor)); + + if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src, + (AvbDescriptor*)dest)) + return false; + + if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_PROPERTY) { + avb_error("Invalid tag for property descriptor.\n"); + return false; + } + + dest->key_num_bytes = avb_be64toh(dest->key_num_bytes); + dest->value_num_bytes = avb_be64toh(dest->value_num_bytes); + + /* Check that key and value are fully contained. */ + expected_size = sizeof(AvbPropertyDescriptor) - sizeof(AvbDescriptor) + 2; + if (!avb_safe_add_to(&expected_size, dest->key_num_bytes) || + !avb_safe_add_to(&expected_size, dest->value_num_bytes)) { + avb_error("Overflow while adding up sizes.\n"); + return false; + } + if (expected_size > dest->parent_descriptor.num_bytes_following) { + avb_error("Descriptor payload size overflow.\n"); + return false; + } + + return true; +} + +typedef struct { + const char* key; + size_t key_size; + const char* ret_value; + size_t ret_value_size; +} PropertyIteratorData; + +static bool property_lookup_desc_foreach(const AvbDescriptor* header, + void* user_data) { + PropertyIteratorData* data = (PropertyIteratorData*)user_data; + AvbPropertyDescriptor prop_desc; + const uint8_t* p; + bool ret = true; + + if (header->tag != AVB_DESCRIPTOR_TAG_PROPERTY) { + goto out; + } + + if (!avb_property_descriptor_validate_and_byteswap( + (const AvbPropertyDescriptor*)header, &prop_desc)) { + goto out; + } + + p = (const uint8_t*)header; + if (p[sizeof(AvbPropertyDescriptor) + prop_desc.key_num_bytes] != 0) { + avb_error("No terminating NUL byte in key.\n"); + goto out; + } + + if (data->key_size == prop_desc.key_num_bytes) { + if (avb_memcmp(p + sizeof(AvbPropertyDescriptor), + data->key, + data->key_size) == 0) { + data->ret_value = (const char*)(p + sizeof(AvbPropertyDescriptor) + + prop_desc.key_num_bytes + 1); + data->ret_value_size = prop_desc.value_num_bytes; + /* Stop iterating. */ + ret = false; + goto out; + } + } + +out: + return ret; +} + +const char* avb_property_lookup(const uint8_t* image_data, + size_t image_size, + const char* key, + size_t key_size, + size_t* out_value_size) { + PropertyIteratorData data; + + if (key_size == 0) { + key_size = avb_strlen(key); + } + + data.key = key; + data.key_size = key_size; + + if (avb_descriptor_foreach( + image_data, image_size, property_lookup_desc_foreach, &data) == 0) { + if (out_value_size != NULL) { + *out_value_size = data.ret_value_size; + } + return data.ret_value; + } + + if (out_value_size != NULL) { + *out_value_size = 0; + } + return NULL; +} + +bool avb_property_lookup_uint64(const uint8_t* image_data, + size_t image_size, + const char* key, + size_t key_size, + uint64_t* out_value) { + const char* value; + bool ret = false; + uint64_t parsed_val; + int base; + int n; + + value = avb_property_lookup(image_data, image_size, key, key_size, NULL); + if (value == NULL) { + goto out; + } + + base = 10; + if (avb_memcmp(value, "0x", 2) == 0) { + base = 16; + value += 2; + } + + parsed_val = 0; + for (n = 0; value[n] != '\0'; n++) { + int c = value[n]; + int digit; + + parsed_val *= base; + + if (c >= '0' && c <= '9') { + digit = c - '0'; + } else if (base == 16 && c >= 'a' && c <= 'f') { + digit = c - 'a' + 10; + } else if (base == 16 && c >= 'A' && c <= 'F') { + digit = c - 'A' + 10; + } else { + avb_error("Invalid digit.\n"); + goto out; + } + + parsed_val += digit; + } + + ret = true; + if (out_value != NULL) { + *out_value = parsed_val; + } + +out: + return ret; +} diff --git a/libavb/avb_property_descriptor.h b/libavb/avb_property_descriptor.h new file mode 100644 index 0000000..a2fef69 --- a/dev/null +++ b/libavb/avb_property_descriptor.h @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_PROPERTY_DESCRIPTOR_H_ +#define AVB_PROPERTY_DESCRIPTOR_H_ + +#include "avb_descriptor.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* A descriptor for properties (free-form key/value pairs). + * + * Following this struct are |key_num_bytes| bytes of key data, + * followed by a NUL byte, then |value_num_bytes| bytes of value data, + * followed by a NUL byte and then enough padding to make the combined + * size a multiple of 8. + */ +typedef struct AvbPropertyDescriptor { + AvbDescriptor parent_descriptor; + uint64_t key_num_bytes; + uint64_t value_num_bytes; +} AVB_ATTR_PACKED AvbPropertyDescriptor; + +/* Copies |src| to |dest| and validates, byte-swapping fields in the + * process if needed. Returns true if valid, false if invalid. + * + * Data following the struct is not validated nor copied. + */ +bool avb_property_descriptor_validate_and_byteswap( + const AvbPropertyDescriptor* src, + AvbPropertyDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Convenience function for looking up the value for a property with + * name |key| in a vbmeta image. If |key_size| is 0, |key| must be + * NUL-terminated. + * + * The |image_data| parameter must be a pointer to a vbmeta image of + * size |image_size|. + * + * This function returns a pointer to the value inside the passed-in + * image or NULL if not found. Note that the value is always + * guaranteed to be followed by a NUL byte. + * + * If the value was found and |out_value_size| is not NULL, the size + * of the value is returned there. + * + * This function is O(n) in number of descriptors so if you need to + * look up a lot of values, you may want to build a more efficient + * lookup-table by manually walking all descriptors using + * avb_descriptor_foreach(). + * + * Before using this function, you MUST verify |image_data| with + * avb_vbmeta_image_verify() and reject it unless it's signed by a + * known good public key. + */ +const char* avb_property_lookup(const uint8_t* image_data, + size_t image_size, + const char* key, + size_t key_size, + size_t* out_value_size) + AVB_ATTR_WARN_UNUSED_RESULT; + +/* Like avb_property_lookup() but parses the intial portions of the + * value as an unsigned 64-bit integer. Both decimal and hexadecimal + * representations (e.g. "0x2a") are supported. Returns false on + * failure and true on success. On success, the parsed value is + * returned in |out_value|. + */ +bool avb_property_lookup_uint64(const uint8_t* image_data, + size_t image_size, + const char* key, + size_t key_size, + uint64_t* out_value) + AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_PROPERTY_DESCRIPTOR_H_ */ diff --git a/libavb/avb_rsa.c b/libavb/avb_rsa.c new file mode 100644 index 0000000..dcecc16 --- a/dev/null +++ b/libavb/avb_rsa.c @@ -0,0 +1,299 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* Implementation of RSA signature verification which uses a pre-processed + * key for computation. The code extends libmincrypt RSA verification code to + * support multiple RSA key lengths and hash digest algorithms. + */ + +#include "avb_rsa.h" +#include "avb_sha.h" +#include "avb_util.h" +#include "avb_vbmeta_image.h" + +typedef struct Key { + unsigned int len; /* Length of n[] in number of uint32_t */ + uint32_t n0inv; /* -1 / n[0] mod 2^32 */ + uint32_t* n; /* modulus as array (host-byte order) */ + uint32_t* rr; /* R^2 as array (host-byte order) */ +} Key; + +Key* parse_key_data(const uint8_t* data, size_t length) { + AvbRSAPublicKeyHeader h; + Key* key = NULL; + size_t expected_length; + unsigned int i; + const uint8_t* n; + const uint8_t* rr; + + if (!avb_rsa_public_key_header_validate_and_byteswap( + (const AvbRSAPublicKeyHeader*)data, &h)) { + avb_error("Invalid key.\n"); + goto fail; + } + + if (!(h.key_num_bits == 2048 || h.key_num_bits == 4096 || + h.key_num_bits == 8192)) { + avb_error("Unexpected key length.\n"); + goto fail; + } + + expected_length = sizeof(AvbRSAPublicKeyHeader) + 2 * h.key_num_bits / 8; + if (length != expected_length) { + avb_error("Key does not match expected length.\n"); + goto fail; + } + + n = data + sizeof(AvbRSAPublicKeyHeader); + rr = data + sizeof(AvbRSAPublicKeyHeader) + h.key_num_bits / 8; + + /* Store n and rr following the key header so we only have to do one + * allocation. + */ + key = (Key*)(avb_malloc(sizeof(Key) + 2 * h.key_num_bits / 8)); + if (key == NULL) { + goto fail; + } + + key->len = h.key_num_bits / 32; + key->n0inv = h.n0inv; + key->n = (uint32_t*)(key + 1); /* Skip ahead sizeof(Key) bytes. */ + key->rr = key->n + key->len; + + /* Crypto-code below (modpowF4() and friends) expects the key in + * little-endian format (rather than the format we're storing the + * key in), so convert it. + */ + for (i = 0; i < key->len; i++) { + key->n[i] = avb_be32toh(((uint32_t*)n)[key->len - i - 1]); + key->rr[i] = avb_be32toh(((uint32_t*)rr)[key->len - i - 1]); + } + return key; + +fail: + if (key != NULL) { + avb_free(key); + } + return NULL; +} + +void free_parsed_key(Key* key) { + avb_free(key); +} + +/* a[] -= mod */ +static void subM(const Key* key, uint32_t* a) { + int64_t A = 0; + uint32_t i; + for (i = 0; i < key->len; ++i) { + A += (uint64_t)a[i] - key->n[i]; + a[i] = (uint32_t)A; + A >>= 32; + } +} + +/* return a[] >= mod */ +static int geM(const Key* key, uint32_t* a) { + uint32_t i; + for (i = key->len; i;) { + --i; + if (a[i] < key->n[i]) { + return 0; + } + if (a[i] > key->n[i]) { + return 1; + } + } + return 1; /* equal */ +} + +/* montgomery c[] += a * b[] / R % mod */ +static void montMulAdd(const Key* key, + uint32_t* c, + const uint32_t a, + const uint32_t* b) { + uint64_t A = (uint64_t)a * b[0] + c[0]; + uint32_t d0 = (uint32_t)A * key->n0inv; + uint64_t B = (uint64_t)d0 * key->n[0] + (uint32_t)A; + uint32_t i; + + for (i = 1; i < key->len; ++i) { + A = (A >> 32) + (uint64_t)a * b[i] + c[i]; + B = (B >> 32) + (uint64_t)d0 * key->n[i] + (uint32_t)A; + c[i - 1] = (uint32_t)B; + } + + A = (A >> 32) + (B >> 32); + + c[i - 1] = (uint32_t)A; + + if (A >> 32) { + subM(key, c); + } +} + +/* montgomery c[] = a[] * b[] / R % mod */ +static void montMul(const Key* key, uint32_t* c, uint32_t* a, uint32_t* b) { + uint32_t i; + for (i = 0; i < key->len; ++i) { + c[i] = 0; + } + for (i = 0; i < key->len; ++i) { + montMulAdd(key, c, a[i], b); + } +} + +/* In-place public exponentiation. (65537} + * Input and output big-endian byte array in inout. + */ +static void modpowF4(const Key* key, uint8_t* inout) { + uint32_t* a = (uint32_t*)avb_malloc(key->len * sizeof(uint32_t)); + uint32_t* aR = (uint32_t*)avb_malloc(key->len * sizeof(uint32_t)); + uint32_t* aaR = (uint32_t*)avb_malloc(key->len * sizeof(uint32_t)); + if (a == NULL || aR == NULL || aaR == NULL) { + goto out; + } + + uint32_t* aaa = aaR; /* Re-use location. */ + int i; + + /* Convert from big endian byte array to little endian word array. */ + for (i = 0; i < (int)key->len; ++i) { + uint32_t tmp = (inout[((key->len - 1 - i) * 4) + 0] << 24) | + (inout[((key->len - 1 - i) * 4) + 1] << 16) | + (inout[((key->len - 1 - i) * 4) + 2] << 8) | + (inout[((key->len - 1 - i) * 4) + 3] << 0); + a[i] = tmp; + } + + montMul(key, aR, a, key->rr); /* aR = a * RR / R mod M */ + for (i = 0; i < 16; i += 2) { + montMul(key, aaR, aR, aR); /* aaR = aR * aR / R mod M */ + montMul(key, aR, aaR, aaR); /* aR = aaR * aaR / R mod M */ + } + montMul(key, aaa, aR, a); /* aaa = aR * a / R mod M */ + + /* Make sure aaa < mod; aaa is at most 1x mod too large. */ + if (geM(key, aaa)) { + subM(key, aaa); + } + + /* Convert to bigendian byte array */ + for (i = (int)key->len - 1; i >= 0; --i) { + uint32_t tmp = aaa[i]; + *inout++ = (uint8_t)(tmp >> 24); + *inout++ = (uint8_t)(tmp >> 16); + *inout++ = (uint8_t)(tmp >> 8); + *inout++ = (uint8_t)(tmp >> 0); + } + +out: + if (a != NULL) { + avb_free(a); + } + if (aR != NULL) { + avb_free(aR); + } + if (aaR != NULL) { + avb_free(aaR); + } +} + +/* Verify a RSA PKCS1.5 signature against an expected hash. + * Returns false on failure, true on success. + */ +bool avb_rsa_verify(const uint8_t* key, + size_t key_num_bytes, + const uint8_t* sig, + size_t sig_num_bytes, + const uint8_t* hash, + size_t hash_num_bytes, + const uint8_t* padding, + size_t padding_num_bytes) { + uint8_t* buf = NULL; + Key* parsed_key = NULL; + bool success = false; + + if (key == NULL || sig == NULL || hash == NULL || padding == NULL) { + avb_error("Invalid input.\n"); + goto out; + } + + parsed_key = parse_key_data(key, key_num_bytes); + if (parsed_key == NULL) { + avb_error("Error parsing key.\n"); + goto out; + } + + if (sig_num_bytes != (parsed_key->len * sizeof(uint32_t))) { + avb_error("Signature length does not match key length.\n"); + goto out; + } + + if (padding_num_bytes != sig_num_bytes - hash_num_bytes) { + avb_error("Padding length does not match hash and signature lengths.\n"); + goto out; + } + + buf = (uint8_t*)avb_malloc(sig_num_bytes); + if (buf == NULL) { + avb_error("Error allocating memory.\n"); + goto out; + } + avb_memcpy(buf, sig, sig_num_bytes); + + modpowF4(parsed_key, buf); + + /* Check padding bytes. + * + * Even though there are probably no timing issues here, we use + * avb_safe_memcmp() just to be on the safe side. + */ + if (avb_safe_memcmp(buf, padding, padding_num_bytes)) { + avb_error("Padding check failed.\n"); + goto out; + } + + /* Check hash. */ + if (avb_safe_memcmp(buf + padding_num_bytes, hash, hash_num_bytes)) { + avb_error("Hash check failed.\n"); + goto out; + } + + success = true; + +out: + if (parsed_key != NULL) { + free_parsed_key(parsed_key); + } + if (buf != NULL) { + avb_free(buf); + } + return success; +} diff --git a/libavb/avb_rsa.h b/libavb/avb_rsa.h new file mode 100644 index 0000000..c2dcf47 --- a/dev/null +++ b/libavb/avb_rsa.h @@ -0,0 +1,73 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifdef AVB_INSIDE_LIBAVB_H +#error "You can't include avb_rsa.h in the public header libavb.h." +#endif + +#ifndef AVB_COMPILATION +#error "Never include this file, it may only be used from internal avb code." +#endif + +#ifndef AVB_RSA_H_ +#define AVB_RSA_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +#include "avb_crypto.h" +#include "avb_sysdeps.h" + +/* Using the key given by |key|, verify a RSA signature |sig| of + * length |sig_num_bytes| against an expected |hash| of length + * |hash_num_bytes|. The padding to expect must be passed in using + * |padding| of length |padding_num_bytes|. + * + * The data in |key| must match the format defined in + * |AvbRSAPublicKeyHeader|, including the two large numbers + * following. The |key_num_bytes| must be the size of the entire + * serialized key. + * + * Returns false if verification fails, true otherwise. + */ +bool avb_rsa_verify(const uint8_t* key, + size_t key_num_bytes, + const uint8_t* sig, + size_t sig_num_bytes, + const uint8_t* hash, + size_t hash_num_bytes, + const uint8_t* padding, + size_t padding_num_bytes) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_RSA_H_ */ diff --git a/libavb/avb_sha.h b/libavb/avb_sha.h new file mode 100644 index 0000000..c5a6a4c --- a/dev/null +++ b/libavb/avb_sha.h @@ -0,0 +1,90 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifdef AVB_INSIDE_LIBAVB_H +#error "You can't include avb_sha.h in the public header libavb.h." +#endif + +#ifndef AVB_COMPILATION +#error "Never include this file, it may only be used from internal avb code." +#endif + +#ifndef AVB_SHA_H_ +#define AVB_SHA_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +#include "avb_crypto.h" +#include "avb_sysdeps.h" + +/* Block size in bytes of a SHA-256 digest. */ +#define AVB_SHA256_BLOCK_SIZE 64 + + +/* Block size in bytes of a SHA-512 digest. */ +#define AVB_SHA512_BLOCK_SIZE 128 + +/* Data structure used for SHA-256. */ +typedef struct { + uint32_t h[8]; + uint32_t tot_len; + uint32_t len; + uint8_t block[2 * AVB_SHA256_BLOCK_SIZE]; + uint8_t buf[AVB_SHA256_DIGEST_SIZE]; /* Used for storing the final digest. */ +} AvbSHA256Ctx; + +/* Data structure used for SHA-512. */ +typedef struct { + uint64_t h[8]; + uint32_t tot_len; + uint32_t len; + uint8_t block[2 * AVB_SHA512_BLOCK_SIZE]; + uint8_t buf[AVB_SHA512_DIGEST_SIZE]; /* Used for storing the final digest. */ +} AvbSHA512Ctx; + +/* Initializes the SHA-256 context. */ +void avb_sha256_init(AvbSHA256Ctx* ctx); + +/* Updates the SHA-256 context with |len| bytes from |data|. */ +void avb_sha256_update(AvbSHA256Ctx* ctx, const uint8_t* data, uint32_t len); + +/* Returns the SHA-256 digest. */ +uint8_t* avb_sha256_final(AvbSHA256Ctx* ctx) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Initializes the SHA-512 context. */ +void avb_sha512_init(AvbSHA512Ctx* ctx); + +/* Updates the SHA-512 context with |len| bytes from |data|. */ +void avb_sha512_update(AvbSHA512Ctx* ctx, const uint8_t* data, uint32_t len); + +/* Returns the SHA-512 digest. */ +uint8_t* avb_sha512_final(AvbSHA512Ctx* ctx) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_SHA_H_ */ diff --git a/libavb/avb_sha256.c b/libavb/avb_sha256.c new file mode 100644 index 0000000..cdd143a --- a/dev/null +++ b/libavb/avb_sha256.c @@ -0,0 +1,390 @@ +/* SHA-256 and SHA-512 implementation based on code by Oliver Gay + * <olivier.gay@a3.epfl.ch> under a BSD-style license. See below. + */ + +/* + * FIPS 180-2 SHA-224/256/384/512 implementation + * Last update: 02/02/2007 + * Issue date: 04/30/2005 + * + * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "avb_sha.h" + +#define SHFR(x, n) (x >> n) +#define ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n))) +#define ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n))) +#define CH(x, y, z) ((x & y) ^ (~x & z)) +#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) + +#define SHA256_F1(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) +#define SHA256_F2(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) +#define SHA256_F3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHFR(x, 3)) +#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10)) + +#define UNPACK32(x, str) \ + { \ + *((str) + 3) = (uint8_t)((x)); \ + *((str) + 2) = (uint8_t)((x) >> 8); \ + *((str) + 1) = (uint8_t)((x) >> 16); \ + *((str) + 0) = (uint8_t)((x) >> 24); \ + } + +#define PACK32(str, x) \ + { \ + *(x) = ((uint32_t) * ((str) + 3)) | ((uint32_t) * ((str) + 2) << 8) | \ + ((uint32_t) * ((str) + 1) << 16) | \ + ((uint32_t) * ((str) + 0) << 24); \ + } + +/* Macros used for loops unrolling */ + +#define SHA256_SCR(i) \ + { w[i] = SHA256_F4(w[i - 2]) + w[i - 7] + SHA256_F3(w[i - 15]) + w[i - 16]; } + +#define SHA256_EXP(a, b, c, d, e, f, g, h, j) \ + { \ + t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) + sha256_k[j] + \ + w[j]; \ + t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]); \ + wv[d] += t1; \ + wv[h] = t1 + t2; \ + } + +static const uint32_t sha256_h0[8] = {0x6a09e667, + 0xbb67ae85, + 0x3c6ef372, + 0xa54ff53a, + 0x510e527f, + 0x9b05688c, + 0x1f83d9ab, + 0x5be0cd19}; + +static const uint32_t sha256_k[64] = { + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, + 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, + 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, + 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, + 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, + 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, + 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, + 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, + 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2}; + +/* SHA-256 implementation */ +void avb_sha256_init(AvbSHA256Ctx* ctx) { +#ifndef UNROLL_LOOPS + int i; + for (i = 0; i < 8; i++) { + ctx->h[i] = sha256_h0[i]; + } +#else + ctx->h[0] = sha256_h0[0]; + ctx->h[1] = sha256_h0[1]; + ctx->h[2] = sha256_h0[2]; + ctx->h[3] = sha256_h0[3]; + ctx->h[4] = sha256_h0[4]; + ctx->h[5] = sha256_h0[5]; + ctx->h[6] = sha256_h0[6]; + ctx->h[7] = sha256_h0[7]; +#endif /* !UNROLL_LOOPS */ + + ctx->len = 0; + ctx->tot_len = 0; +} + +static void SHA256_transform(AvbSHA256Ctx* ctx, + const uint8_t* message, + unsigned int block_nb) { + uint32_t w[64]; + uint32_t wv[8]; + uint32_t t1, t2; + const unsigned char* sub_block; + int i; + +#ifndef UNROLL_LOOPS + int j; +#endif + + for (i = 0; i < (int)block_nb; i++) { + sub_block = message + (i << 6); + +#ifndef UNROLL_LOOPS + for (j = 0; j < 16; j++) { + PACK32(&sub_block[j << 2], &w[j]); + } + + for (j = 16; j < 64; j++) { + SHA256_SCR(j); + } + + for (j = 0; j < 8; j++) { + wv[j] = ctx->h[j]; + } + + for (j = 0; j < 64; j++) { + t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha256_k[j] + + w[j]; + t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]); + wv[7] = wv[6]; + wv[6] = wv[5]; + wv[5] = wv[4]; + wv[4] = wv[3] + t1; + wv[3] = wv[2]; + wv[2] = wv[1]; + wv[1] = wv[0]; + wv[0] = t1 + t2; + } + + for (j = 0; j < 8; j++) { + ctx->h[j] += wv[j]; + } +#else + PACK32(&sub_block[0], &w[0]); + PACK32(&sub_block[4], &w[1]); + PACK32(&sub_block[8], &w[2]); + PACK32(&sub_block[12], &w[3]); + PACK32(&sub_block[16], &w[4]); + PACK32(&sub_block[20], &w[5]); + PACK32(&sub_block[24], &w[6]); + PACK32(&sub_block[28], &w[7]); + PACK32(&sub_block[32], &w[8]); + PACK32(&sub_block[36], &w[9]); + PACK32(&sub_block[40], &w[10]); + PACK32(&sub_block[44], &w[11]); + PACK32(&sub_block[48], &w[12]); + PACK32(&sub_block[52], &w[13]); + PACK32(&sub_block[56], &w[14]); + PACK32(&sub_block[60], &w[15]); + + SHA256_SCR(16); + SHA256_SCR(17); + SHA256_SCR(18); + SHA256_SCR(19); + SHA256_SCR(20); + SHA256_SCR(21); + SHA256_SCR(22); + SHA256_SCR(23); + SHA256_SCR(24); + SHA256_SCR(25); + SHA256_SCR(26); + SHA256_SCR(27); + SHA256_SCR(28); + SHA256_SCR(29); + SHA256_SCR(30); + SHA256_SCR(31); + SHA256_SCR(32); + SHA256_SCR(33); + SHA256_SCR(34); + SHA256_SCR(35); + SHA256_SCR(36); + SHA256_SCR(37); + SHA256_SCR(38); + SHA256_SCR(39); + SHA256_SCR(40); + SHA256_SCR(41); + SHA256_SCR(42); + SHA256_SCR(43); + SHA256_SCR(44); + SHA256_SCR(45); + SHA256_SCR(46); + SHA256_SCR(47); + SHA256_SCR(48); + SHA256_SCR(49); + SHA256_SCR(50); + SHA256_SCR(51); + SHA256_SCR(52); + SHA256_SCR(53); + SHA256_SCR(54); + SHA256_SCR(55); + SHA256_SCR(56); + SHA256_SCR(57); + SHA256_SCR(58); + SHA256_SCR(59); + SHA256_SCR(60); + SHA256_SCR(61); + SHA256_SCR(62); + SHA256_SCR(63); + + wv[0] = ctx->h[0]; + wv[1] = ctx->h[1]; + wv[2] = ctx->h[2]; + wv[3] = ctx->h[3]; + wv[4] = ctx->h[4]; + wv[5] = ctx->h[5]; + wv[6] = ctx->h[6]; + wv[7] = ctx->h[7]; + + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 0); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 1); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 2); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 3); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 4); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 5); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 6); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 7); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 8); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 9); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 10); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 11); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 12); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 13); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 14); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 15); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 16); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 17); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 18); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 19); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 20); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 21); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 22); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 23); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 24); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 25); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 26); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 27); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 28); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 29); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 30); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 31); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 32); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 33); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 34); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 35); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 36); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 37); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 38); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 39); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 40); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 41); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 42); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 43); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 44); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 45); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 46); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 47); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 48); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 49); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 50); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 51); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 52); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 53); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 54); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 55); + SHA256_EXP(0, 1, 2, 3, 4, 5, 6, 7, 56); + SHA256_EXP(7, 0, 1, 2, 3, 4, 5, 6, 57); + SHA256_EXP(6, 7, 0, 1, 2, 3, 4, 5, 58); + SHA256_EXP(5, 6, 7, 0, 1, 2, 3, 4, 59); + SHA256_EXP(4, 5, 6, 7, 0, 1, 2, 3, 60); + SHA256_EXP(3, 4, 5, 6, 7, 0, 1, 2, 61); + SHA256_EXP(2, 3, 4, 5, 6, 7, 0, 1, 62); + SHA256_EXP(1, 2, 3, 4, 5, 6, 7, 0, 63); + + ctx->h[0] += wv[0]; + ctx->h[1] += wv[1]; + ctx->h[2] += wv[2]; + ctx->h[3] += wv[3]; + ctx->h[4] += wv[4]; + ctx->h[5] += wv[5]; + ctx->h[6] += wv[6]; + ctx->h[7] += wv[7]; +#endif /* !UNROLL_LOOPS */ + } +} + +void avb_sha256_update(AvbSHA256Ctx* ctx, const uint8_t* data, uint32_t len) { + unsigned int block_nb; + unsigned int new_len, rem_len, tmp_len; + const uint8_t* shifted_data; + + tmp_len = AVB_SHA256_BLOCK_SIZE - ctx->len; + rem_len = len < tmp_len ? len : tmp_len; + + avb_memcpy(&ctx->block[ctx->len], data, rem_len); + + if (ctx->len + len < AVB_SHA256_BLOCK_SIZE) { + ctx->len += len; + return; + } + + new_len = len - rem_len; + block_nb = new_len / AVB_SHA256_BLOCK_SIZE; + + shifted_data = data + rem_len; + + SHA256_transform(ctx, ctx->block, 1); + SHA256_transform(ctx, shifted_data, block_nb); + + rem_len = new_len % AVB_SHA256_BLOCK_SIZE; + + avb_memcpy(ctx->block, &shifted_data[block_nb << 6], rem_len); + + ctx->len = rem_len; + ctx->tot_len += (block_nb + 1) << 6; +} + +uint8_t* avb_sha256_final(AvbSHA256Ctx* ctx) { + unsigned int block_nb; + unsigned int pm_len; + unsigned int len_b; +#ifndef UNROLL_LOOPS + int i; +#endif + + block_nb = + (1 + ((AVB_SHA256_BLOCK_SIZE - 9) < (ctx->len % AVB_SHA256_BLOCK_SIZE))); + + len_b = (ctx->tot_len + ctx->len) << 3; + pm_len = block_nb << 6; + + avb_memset(ctx->block + ctx->len, 0, pm_len - ctx->len); + ctx->block[ctx->len] = 0x80; + UNPACK32(len_b, ctx->block + pm_len - 4); + + SHA256_transform(ctx, ctx->block, block_nb); + +#ifndef UNROLL_LOOPS + for (i = 0; i < 8; i++) { + UNPACK32(ctx->h[i], &ctx->buf[i << 2]); + } +#else + UNPACK32(ctx->h[0], &ctx->buf[0]); + UNPACK32(ctx->h[1], &ctx->buf[4]); + UNPACK32(ctx->h[2], &ctx->buf[8]); + UNPACK32(ctx->h[3], &ctx->buf[12]); + UNPACK32(ctx->h[4], &ctx->buf[16]); + UNPACK32(ctx->h[5], &ctx->buf[20]); + UNPACK32(ctx->h[6], &ctx->buf[24]); + UNPACK32(ctx->h[7], &ctx->buf[28]); +#endif /* !UNROLL_LOOPS */ + + return ctx->buf; +} diff --git a/libavb/avb_sha512.c b/libavb/avb_sha512.c new file mode 100644 index 0000000..8df6319 --- a/dev/null +++ b/libavb/avb_sha512.c @@ -0,0 +1,388 @@ +/* SHA-256 and SHA-512 implementation based on code by Oliver Gay + * <olivier.gay@a3.epfl.ch> under a BSD-style license. See below. + */ + +/* + * FIPS 180-2 SHA-224/256/384/512 implementation + * Last update: 02/02/2007 + * Issue date: 04/30/2005 + * + * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "avb_sha.h" + +#define SHFR(x, n) (x >> n) +#define ROTR(x, n) ((x >> n) | (x << ((sizeof(x) << 3) - n))) +#define ROTL(x, n) ((x << n) | (x >> ((sizeof(x) << 3) - n))) +#define CH(x, y, z) ((x & y) ^ (~x & z)) +#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z)) + +#define SHA512_F1(x) (ROTR(x, 28) ^ ROTR(x, 34) ^ ROTR(x, 39)) +#define SHA512_F2(x) (ROTR(x, 14) ^ ROTR(x, 18) ^ ROTR(x, 41)) +#define SHA512_F3(x) (ROTR(x, 1) ^ ROTR(x, 8) ^ SHFR(x, 7)) +#define SHA512_F4(x) (ROTR(x, 19) ^ ROTR(x, 61) ^ SHFR(x, 6)) + +#define UNPACK32(x, str) \ + { \ + *((str) + 3) = (uint8_t)((x)); \ + *((str) + 2) = (uint8_t)((x) >> 8); \ + *((str) + 1) = (uint8_t)((x) >> 16); \ + *((str) + 0) = (uint8_t)((x) >> 24); \ + } + +#define UNPACK64(x, str) \ + { \ + *((str) + 7) = (uint8_t)x; \ + *((str) + 6) = (uint8_t)((uint64_t)x >> 8); \ + *((str) + 5) = (uint8_t)((uint64_t)x >> 16); \ + *((str) + 4) = (uint8_t)((uint64_t)x >> 24); \ + *((str) + 3) = (uint8_t)((uint64_t)x >> 32); \ + *((str) + 2) = (uint8_t)((uint64_t)x >> 40); \ + *((str) + 1) = (uint8_t)((uint64_t)x >> 48); \ + *((str) + 0) = (uint8_t)((uint64_t)x >> 56); \ + } + +#define PACK64(str, x) \ + { \ + *(x) = \ + ((uint64_t) * ((str) + 7)) | ((uint64_t) * ((str) + 6) << 8) | \ + ((uint64_t) * ((str) + 5) << 16) | ((uint64_t) * ((str) + 4) << 24) | \ + ((uint64_t) * ((str) + 3) << 32) | ((uint64_t) * ((str) + 2) << 40) | \ + ((uint64_t) * ((str) + 1) << 48) | ((uint64_t) * ((str) + 0) << 56); \ + } + +/* Macros used for loops unrolling */ + +#define SHA512_SCR(i) \ + { w[i] = SHA512_F4(w[i - 2]) + w[i - 7] + SHA512_F3(w[i - 15]) + w[i - 16]; } + +#define SHA512_EXP(a, b, c, d, e, f, g, h, j) \ + { \ + t1 = wv[h] + SHA512_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) + sha512_k[j] + \ + w[j]; \ + t2 = SHA512_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]); \ + wv[d] += t1; \ + wv[h] = t1 + t2; \ + } + +static const uint64_t sha512_h0[8] = {0x6a09e667f3bcc908ULL, + 0xbb67ae8584caa73bULL, + 0x3c6ef372fe94f82bULL, + 0xa54ff53a5f1d36f1ULL, + 0x510e527fade682d1ULL, + 0x9b05688c2b3e6c1fULL, + 0x1f83d9abfb41bd6bULL, + 0x5be0cd19137e2179ULL}; + +static const uint64_t sha512_k[80] = { + 0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, + 0xe9b5dba58189dbbcULL, 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, + 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, 0xd807aa98a3030242ULL, + 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL, + 0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, + 0xc19bf174cf692694ULL, 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, + 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, 0x2de92c6f592b0275ULL, + 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL, + 0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, + 0xbf597fc7beef0ee4ULL, 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, + 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, 0x27b70a8546d22ffcULL, + 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL, + 0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, + 0x92722c851482353bULL, 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, + 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, 0xd192e819d6ef5218ULL, + 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL, + 0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, + 0x34b0bcb5e19b48a8ULL, 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, + 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, 0x748f82ee5defb2fcULL, + 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL, + 0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, + 0xc67178f2e372532bULL, 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, + 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, 0x06f067aa72176fbaULL, + 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL, + 0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, + 0x431d67c49c100d4cULL, 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, + 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL}; + +/* SHA-512 implementation */ + +void avb_sha512_init(AvbSHA512Ctx* ctx) { +#ifdef UNROLL_LOOPS_SHA512 + ctx->h[0] = sha512_h0[0]; + ctx->h[1] = sha512_h0[1]; + ctx->h[2] = sha512_h0[2]; + ctx->h[3] = sha512_h0[3]; + ctx->h[4] = sha512_h0[4]; + ctx->h[5] = sha512_h0[5]; + ctx->h[6] = sha512_h0[6]; + ctx->h[7] = sha512_h0[7]; +#else + int i; + + for (i = 0; i < 8; i++) + ctx->h[i] = sha512_h0[i]; +#endif /* UNROLL_LOOPS_SHA512 */ + + ctx->len = 0; + ctx->tot_len = 0; +} + +static void SHA512_transform(AvbSHA512Ctx* ctx, + const uint8_t* message, + unsigned int block_nb) { + uint64_t w[80]; + uint64_t wv[8]; + uint64_t t1, t2; + const uint8_t* sub_block; + int i, j; + + for (i = 0; i < (int)block_nb; i++) { + sub_block = message + (i << 7); + +#ifdef UNROLL_LOOPS_SHA512 + PACK64(&sub_block[0], &w[0]); + PACK64(&sub_block[8], &w[1]); + PACK64(&sub_block[16], &w[2]); + PACK64(&sub_block[24], &w[3]); + PACK64(&sub_block[32], &w[4]); + PACK64(&sub_block[40], &w[5]); + PACK64(&sub_block[48], &w[6]); + PACK64(&sub_block[56], &w[7]); + PACK64(&sub_block[64], &w[8]); + PACK64(&sub_block[72], &w[9]); + PACK64(&sub_block[80], &w[10]); + PACK64(&sub_block[88], &w[11]); + PACK64(&sub_block[96], &w[12]); + PACK64(&sub_block[104], &w[13]); + PACK64(&sub_block[112], &w[14]); + PACK64(&sub_block[120], &w[15]); + + SHA512_SCR(16); + SHA512_SCR(17); + SHA512_SCR(18); + SHA512_SCR(19); + SHA512_SCR(20); + SHA512_SCR(21); + SHA512_SCR(22); + SHA512_SCR(23); + SHA512_SCR(24); + SHA512_SCR(25); + SHA512_SCR(26); + SHA512_SCR(27); + SHA512_SCR(28); + SHA512_SCR(29); + SHA512_SCR(30); + SHA512_SCR(31); + SHA512_SCR(32); + SHA512_SCR(33); + SHA512_SCR(34); + SHA512_SCR(35); + SHA512_SCR(36); + SHA512_SCR(37); + SHA512_SCR(38); + SHA512_SCR(39); + SHA512_SCR(40); + SHA512_SCR(41); + SHA512_SCR(42); + SHA512_SCR(43); + SHA512_SCR(44); + SHA512_SCR(45); + SHA512_SCR(46); + SHA512_SCR(47); + SHA512_SCR(48); + SHA512_SCR(49); + SHA512_SCR(50); + SHA512_SCR(51); + SHA512_SCR(52); + SHA512_SCR(53); + SHA512_SCR(54); + SHA512_SCR(55); + SHA512_SCR(56); + SHA512_SCR(57); + SHA512_SCR(58); + SHA512_SCR(59); + SHA512_SCR(60); + SHA512_SCR(61); + SHA512_SCR(62); + SHA512_SCR(63); + SHA512_SCR(64); + SHA512_SCR(65); + SHA512_SCR(66); + SHA512_SCR(67); + SHA512_SCR(68); + SHA512_SCR(69); + SHA512_SCR(70); + SHA512_SCR(71); + SHA512_SCR(72); + SHA512_SCR(73); + SHA512_SCR(74); + SHA512_SCR(75); + SHA512_SCR(76); + SHA512_SCR(77); + SHA512_SCR(78); + SHA512_SCR(79); + + wv[0] = ctx->h[0]; + wv[1] = ctx->h[1]; + wv[2] = ctx->h[2]; + wv[3] = ctx->h[3]; + wv[4] = ctx->h[4]; + wv[5] = ctx->h[5]; + wv[6] = ctx->h[6]; + wv[7] = ctx->h[7]; + + j = 0; + + do { + SHA512_EXP(0, 1, 2, 3, 4, 5, 6, 7, j); + j++; + SHA512_EXP(7, 0, 1, 2, 3, 4, 5, 6, j); + j++; + SHA512_EXP(6, 7, 0, 1, 2, 3, 4, 5, j); + j++; + SHA512_EXP(5, 6, 7, 0, 1, 2, 3, 4, j); + j++; + SHA512_EXP(4, 5, 6, 7, 0, 1, 2, 3, j); + j++; + SHA512_EXP(3, 4, 5, 6, 7, 0, 1, 2, j); + j++; + SHA512_EXP(2, 3, 4, 5, 6, 7, 0, 1, j); + j++; + SHA512_EXP(1, 2, 3, 4, 5, 6, 7, 0, j); + j++; + } while (j < 80); + + ctx->h[0] += wv[0]; + ctx->h[1] += wv[1]; + ctx->h[2] += wv[2]; + ctx->h[3] += wv[3]; + ctx->h[4] += wv[4]; + ctx->h[5] += wv[5]; + ctx->h[6] += wv[6]; + ctx->h[7] += wv[7]; +#else + for (j = 0; j < 16; j++) { + PACK64(&sub_block[j << 3], &w[j]); + } + + for (j = 16; j < 80; j++) { + SHA512_SCR(j); + } + + for (j = 0; j < 8; j++) { + wv[j] = ctx->h[j]; + } + + for (j = 0; j < 80; j++) { + t1 = wv[7] + SHA512_F2(wv[4]) + CH(wv[4], wv[5], wv[6]) + sha512_k[j] + + w[j]; + t2 = SHA512_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]); + wv[7] = wv[6]; + wv[6] = wv[5]; + wv[5] = wv[4]; + wv[4] = wv[3] + t1; + wv[3] = wv[2]; + wv[2] = wv[1]; + wv[1] = wv[0]; + wv[0] = t1 + t2; + } + + for (j = 0; j < 8; j++) + ctx->h[j] += wv[j]; +#endif /* UNROLL_LOOPS_SHA512 */ + } +} + +void avb_sha512_update(AvbSHA512Ctx* ctx, const uint8_t* data, uint32_t len) { + unsigned int block_nb; + unsigned int new_len, rem_len, tmp_len; + const uint8_t* shifted_data; + + tmp_len = AVB_SHA512_BLOCK_SIZE - ctx->len; + rem_len = len < tmp_len ? len : tmp_len; + + avb_memcpy(&ctx->block[ctx->len], data, rem_len); + + if (ctx->len + len < AVB_SHA512_BLOCK_SIZE) { + ctx->len += len; + return; + } + + new_len = len - rem_len; + block_nb = new_len / AVB_SHA512_BLOCK_SIZE; + + shifted_data = data + rem_len; + + SHA512_transform(ctx, ctx->block, 1); + SHA512_transform(ctx, shifted_data, block_nb); + + rem_len = new_len % AVB_SHA512_BLOCK_SIZE; + + avb_memcpy(ctx->block, &shifted_data[block_nb << 7], rem_len); + + ctx->len = rem_len; + ctx->tot_len += (block_nb + 1) << 7; +} + +uint8_t* avb_sha512_final(AvbSHA512Ctx* ctx) { + unsigned int block_nb; + unsigned int pm_len; + unsigned int len_b; + +#ifndef UNROLL_LOOPS_SHA512 + int i; +#endif + + block_nb = + 1 + ((AVB_SHA512_BLOCK_SIZE - 17) < (ctx->len % AVB_SHA512_BLOCK_SIZE)); + + len_b = (ctx->tot_len + ctx->len) << 3; + pm_len = block_nb << 7; + + avb_memset(ctx->block + ctx->len, 0, pm_len - ctx->len); + ctx->block[ctx->len] = 0x80; + UNPACK32(len_b, ctx->block + pm_len - 4); + + SHA512_transform(ctx, ctx->block, block_nb); + +#ifdef UNROLL_LOOPS_SHA512 + UNPACK64(ctx->h[0], &ctx->buf[0]); + UNPACK64(ctx->h[1], &ctx->buf[8]); + UNPACK64(ctx->h[2], &ctx->buf[16]); + UNPACK64(ctx->h[3], &ctx->buf[24]); + UNPACK64(ctx->h[4], &ctx->buf[32]); + UNPACK64(ctx->h[5], &ctx->buf[40]); + UNPACK64(ctx->h[6], &ctx->buf[48]); + UNPACK64(ctx->h[7], &ctx->buf[56]); +#else + for (i = 0; i < 8; i++) + UNPACK64(ctx->h[i], &ctx->buf[i << 3]); +#endif /* UNROLL_LOOPS_SHA512 */ + + return ctx->buf; +} diff --git a/libavb/avb_slot_verify.c b/libavb/avb_slot_verify.c new file mode 100644 index 0000000..469a788 --- a/dev/null +++ b/libavb/avb_slot_verify.c @@ -0,0 +1,1187 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_slot_verify.h" +#include "avb_chain_partition_descriptor.h" +#include "avb_footer.h" +#include "avb_hash_descriptor.h" +#include "avb_kernel_cmdline_descriptor.h" +#include "avb_sha.h" +#include "avb_util.h" +#include "avb_vbmeta_image.h" +#include "avb_version.h" + +/* Maximum allow length (in bytes) of a partition name, including + * ab_suffix. + */ +#define PART_NAME_MAX_SIZE 32 + +/* Maximum number of partitions that can be loaded with avb_slot_verify(). */ +#define MAX_NUMBER_OF_LOADED_PARTITIONS 32 + +/* Maximum number of vbmeta images that can be loaded with avb_slot_verify(). */ +#define MAX_NUMBER_OF_VBMETA_IMAGES 32 + +/* Maximum size of a vbmeta image - 64 KiB. */ +#define VBMETA_MAX_SIZE (64 * 1024) + +/* Helper function to see if we should continue with verification in + * allow_verification_error=true mode if something goes wrong. See the + * comments for the avb_slot_verify() function for more information. + */ +static inline bool result_should_continue(AvbSlotVerifyResult result) { + switch (result) { + case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: + case AVB_SLOT_VERIFY_RESULT_ERROR_IO: + case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: + case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: + return false; + + case AVB_SLOT_VERIFY_RESULT_OK: + case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: + case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: + case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: + return true; + } + + return false; +} + +static AvbSlotVerifyResult load_and_verify_hash_partition( + AvbOps* ops, + const char* const* requested_partitions, + const char* ab_suffix, + bool allow_verification_error, + const AvbDescriptor* descriptor, + AvbSlotVerifyData* slot_data) { + AvbHashDescriptor hash_desc; + const uint8_t* desc_partition_name = NULL; + const uint8_t* desc_salt; + const uint8_t* desc_digest; + char part_name[PART_NAME_MAX_SIZE]; + AvbSlotVerifyResult ret; + AvbIOResult io_ret; + uint8_t* image_buf = NULL; + size_t part_num_read; + uint8_t* digest; + size_t digest_len; + const char* found; + + if (!avb_hash_descriptor_validate_and_byteswap( + (const AvbHashDescriptor*)descriptor, &hash_desc)) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + desc_partition_name = + ((const uint8_t*)descriptor) + sizeof(AvbHashDescriptor); + desc_salt = desc_partition_name + hash_desc.partition_name_len; + desc_digest = desc_salt + hash_desc.salt_len; + + if (!avb_validate_utf8(desc_partition_name, hash_desc.partition_name_len)) { + avb_error("Partition name is not valid UTF-8.\n"); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + if (!avb_str_concat(part_name, + sizeof part_name, + (const char*)desc_partition_name, + hash_desc.partition_name_len, + ab_suffix, + avb_strlen(ab_suffix))) { + avb_error("Partition name and suffix does not fit.\n"); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + image_buf = avb_malloc(hash_desc.image_size); + if (image_buf == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } + + io_ret = ops->read_from_partition(ops, + part_name, + 0 /* offset */, + hash_desc.image_size, + image_buf, + &part_num_read); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_errorv(part_name, ": Error loading data from partition.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + if (part_num_read != hash_desc.image_size) { + avb_errorv(part_name, ": Read fewer than requested bytes.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + + if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha256") == 0) { + AvbSHA256Ctx sha256_ctx; + avb_sha256_init(&sha256_ctx); + avb_sha256_update(&sha256_ctx, desc_salt, hash_desc.salt_len); + avb_sha256_update(&sha256_ctx, image_buf, hash_desc.image_size); + digest = avb_sha256_final(&sha256_ctx); + digest_len = AVB_SHA256_DIGEST_SIZE; + } else if (avb_strcmp((const char*)hash_desc.hash_algorithm, "sha512") == 0) { + AvbSHA512Ctx sha512_ctx; + avb_sha512_init(&sha512_ctx); + avb_sha512_update(&sha512_ctx, desc_salt, hash_desc.salt_len); + avb_sha512_update(&sha512_ctx, image_buf, hash_desc.image_size); + digest = avb_sha512_final(&sha512_ctx); + digest_len = AVB_SHA512_DIGEST_SIZE; + } else { + avb_errorv(part_name, ": Unsupported hash algorithm.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + if (digest_len != hash_desc.digest_len) { + avb_errorv( + part_name, ": Digest in descriptor not of expected size.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + if (avb_safe_memcmp(digest, desc_digest, digest_len) != 0) { + avb_errorv(part_name, + ": Hash of data does not match digest in descriptor.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; + goto out; + } + + ret = AVB_SLOT_VERIFY_RESULT_OK; + +out: + + if (ret == AVB_SLOT_VERIFY_RESULT_OK || result_should_continue(ret)) { + /* If this is the requested partition, copy to slot_data. */ + found = avb_strv_find_str(requested_partitions, + (const char*)desc_partition_name, + hash_desc.partition_name_len); + if (found != NULL) { + AvbPartitionData* loaded_partition; + if (slot_data->num_loaded_partitions == MAX_NUMBER_OF_LOADED_PARTITIONS) { + avb_errorv(part_name, ": Too many loaded partitions.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + loaded_partition = + &slot_data->loaded_partitions[slot_data->num_loaded_partitions++]; + loaded_partition->partition_name = avb_strdup(found); + loaded_partition->data_size = hash_desc.image_size; + loaded_partition->data = image_buf; + image_buf = NULL; + } + } + +fail: + if (image_buf != NULL) { + avb_free(image_buf); + } + return ret; +} + +static AvbSlotVerifyResult load_and_verify_vbmeta( + AvbOps* ops, + const char* const* requested_partitions, + const char* ab_suffix, + bool allow_verification_error, + AvbVBMetaImageFlags toplevel_vbmeta_flags, + int rollback_index_location, + const char* partition_name, + size_t partition_name_len, + const uint8_t* expected_public_key, + size_t expected_public_key_length, + AvbSlotVerifyData* slot_data, + AvbAlgorithmType* out_algorithm_type) { + char full_partition_name[PART_NAME_MAX_SIZE]; + AvbSlotVerifyResult ret; + AvbIOResult io_ret; + size_t vbmeta_offset; + size_t vbmeta_size; + uint8_t* vbmeta_buf = NULL; + size_t vbmeta_num_read; + AvbVBMetaVerifyResult vbmeta_ret; + const uint8_t* pk_data; + size_t pk_len; + AvbVBMetaImageHeader vbmeta_header; + uint64_t stored_rollback_index; + const AvbDescriptor** descriptors = NULL; + size_t num_descriptors; + size_t n; + bool is_main_vbmeta; + bool is_vbmeta_partition; + AvbVBMetaData* vbmeta_image_data = NULL; + + ret = AVB_SLOT_VERIFY_RESULT_OK; + + avb_assert(slot_data != NULL); + + /* Since we allow top-level vbmeta in 'boot', use + * rollback_index_location to determine whether we're the main + * vbmeta struct. + */ + is_main_vbmeta = (rollback_index_location == 0); + is_vbmeta_partition = (avb_strcmp(partition_name, "vbmeta") == 0); + + if (!avb_validate_utf8((const uint8_t*)partition_name, partition_name_len)) { + avb_error("Partition name is not valid UTF-8.\n"); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + /* Construct full partition name. */ + if (!avb_str_concat(full_partition_name, + sizeof full_partition_name, + partition_name, + partition_name_len, + ab_suffix, + avb_strlen(ab_suffix))) { + avb_error("Partition name and suffix does not fit.\n"); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + avb_debugv("Loading vbmeta struct from partition '", + full_partition_name, + "'.\n", + NULL); + + /* If we're loading from the main vbmeta partition, the vbmeta + * struct is in the beginning. Otherwise we have to locate it via a + * footer. + */ + if (is_vbmeta_partition) { + vbmeta_offset = 0; + vbmeta_size = VBMETA_MAX_SIZE; + } else { + uint8_t footer_buf[AVB_FOOTER_SIZE]; + size_t footer_num_read; + AvbFooter footer; + + io_ret = ops->read_from_partition(ops, + full_partition_name, + -AVB_FOOTER_SIZE, + AVB_FOOTER_SIZE, + footer_buf, + &footer_num_read); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_errorv(full_partition_name, ": Error loading footer.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + avb_assert(footer_num_read == AVB_FOOTER_SIZE); + + if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf, + &footer)) { + avb_errorv(full_partition_name, ": Error validating footer.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + /* Basic footer sanity check since the data is untrusted. */ + if (footer.vbmeta_size > VBMETA_MAX_SIZE) { + avb_errorv( + full_partition_name, ": Invalid vbmeta size in footer.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + vbmeta_offset = footer.vbmeta_offset; + vbmeta_size = footer.vbmeta_size; + } + + vbmeta_buf = avb_malloc(vbmeta_size); + if (vbmeta_buf == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } + + io_ret = ops->read_from_partition(ops, + full_partition_name, + vbmeta_offset, + vbmeta_size, + vbmeta_buf, + &vbmeta_num_read); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + /* If we're looking for 'vbmeta' but there is no such partition, + * go try to get it from the boot partition instead. + */ + if (is_main_vbmeta && io_ret == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION && + is_vbmeta_partition) { + avb_debugv(full_partition_name, + ": No such partition. Trying 'boot' instead.\n", + NULL); + ret = load_and_verify_vbmeta(ops, + requested_partitions, + ab_suffix, + allow_verification_error, + 0 /* toplevel_vbmeta_flags */, + 0 /* rollback_index_location */, + "boot", + avb_strlen("boot"), + NULL /* expected_public_key */, + 0 /* expected_public_key_length */, + slot_data, + out_algorithm_type); + goto out; + } else { + avb_errorv(full_partition_name, ": Error loading vbmeta data.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + } + avb_assert(vbmeta_num_read <= vbmeta_size); + + /* Check if the image is properly signed and get the public key used + * to sign the image. + */ + vbmeta_ret = + avb_vbmeta_image_verify(vbmeta_buf, vbmeta_num_read, &pk_data, &pk_len); + switch (vbmeta_ret) { + case AVB_VBMETA_VERIFY_RESULT_OK: + avb_assert(pk_data != NULL && pk_len > 0); + break; + + case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED: + case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH: + case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH: + ret = AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION; + avb_errorv(full_partition_name, + ": Error verifying vbmeta image: ", + avb_vbmeta_verify_result_to_string(vbmeta_ret), + "\n", + NULL); + if (!allow_verification_error) { + goto out; + } + break; + + case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER: + /* No way to continue this case. */ + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + avb_errorv(full_partition_name, + ": Error verifying vbmeta image: invalid vbmeta header\n", + NULL); + goto out; + + case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION: + /* No way to continue this case. */ + ret = AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION; + avb_errorv(full_partition_name, + ": Error verifying vbmeta image: unsupported AVB version\n", + NULL); + goto out; + } + + /* Byteswap the header. */ + avb_vbmeta_image_header_to_host_byte_order((AvbVBMetaImageHeader*)vbmeta_buf, + &vbmeta_header); + + /* If we're the toplevel, assign flags so they'll be passed down. */ + if (is_main_vbmeta) { + toplevel_vbmeta_flags = (AvbVBMetaImageFlags)vbmeta_header.flags; + } else { + if (vbmeta_header.flags != 0) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + avb_errorv(full_partition_name, + ": chained vbmeta image has non-zero flags\n", + NULL); + goto out; + } + } + + /* Check if key used to make signature matches what is expected. */ + if (pk_data != NULL) { + if (expected_public_key != NULL) { + avb_assert(!is_main_vbmeta); + if (expected_public_key_length != pk_len || + avb_safe_memcmp(expected_public_key, pk_data, pk_len) != 0) { + avb_errorv(full_partition_name, + ": Public key used to sign data does not match key in chain " + "partition descriptor.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; + if (!allow_verification_error) { + goto out; + } + } + } else { + bool key_is_trusted = false; + const uint8_t* pk_metadata = NULL; + size_t pk_metadata_len = 0; + + if (vbmeta_header.public_key_metadata_size > 0) { + pk_metadata = vbmeta_buf + sizeof(AvbVBMetaImageHeader) + + vbmeta_header.authentication_data_block_size + + vbmeta_header.public_key_metadata_offset; + pk_metadata_len = vbmeta_header.public_key_metadata_size; + } + + avb_assert(is_main_vbmeta); + io_ret = ops->validate_vbmeta_public_key( + ops, pk_data, pk_len, pk_metadata, pk_metadata_len, &key_is_trusted); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_errorv(full_partition_name, + ": Error while checking public key used to sign data.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + if (!key_is_trusted) { + avb_errorv(full_partition_name, + ": Public key used to sign data rejected.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED; + if (!allow_verification_error) { + goto out; + } + } + } + } + + /* Check rollback index. */ + io_ret = ops->read_rollback_index( + ops, rollback_index_location, &stored_rollback_index); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_errorv(full_partition_name, + ": Error getting rollback index for location.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto out; + } + if (vbmeta_header.rollback_index < stored_rollback_index) { + avb_errorv( + full_partition_name, + ": Image rollback index is less than the stored rollback index.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX; + if (!allow_verification_error) { + goto out; + } + } + + /* Copy vbmeta to vbmeta_images before recursing. */ + if (is_main_vbmeta) { + avb_assert(slot_data->num_vbmeta_images == 0); + } else { + avb_assert(slot_data->num_vbmeta_images > 0); + } + if (slot_data->num_vbmeta_images == MAX_NUMBER_OF_VBMETA_IMAGES) { + avb_errorv(full_partition_name, ": Too many vbmeta images.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } + vbmeta_image_data = &slot_data->vbmeta_images[slot_data->num_vbmeta_images++]; + vbmeta_image_data->partition_name = avb_strdup(partition_name); + vbmeta_image_data->vbmeta_data = vbmeta_buf; + /* Note that |vbmeta_buf| is actually |vbmeta_num_read| bytes long + * and this includes data past the end of the image. Pass the + * actual size of the vbmeta image. Also, no need to use + * avb_safe_add() since the header has already been verified. + */ + vbmeta_image_data->vbmeta_size = + sizeof(AvbVBMetaImageHeader) + + vbmeta_header.authentication_data_block_size + + vbmeta_header.auxiliary_data_block_size; + vbmeta_image_data->verify_result = vbmeta_ret; + + /* Now go through all descriptors and take the appropriate action: + * + * - hash descriptor: Load data from partition, calculate hash, and + * checks that it matches what's in the hash descriptor. + * + * - hashtree descriptor: Do nothing since verification happens + * on-the-fly from within the OS. + * + * - chained partition descriptor: Load the footer, load the vbmeta + * image, verify vbmeta image (includes rollback checks, hash + * checks, bail on chained partitions). + */ + descriptors = + avb_descriptor_get_all(vbmeta_buf, vbmeta_num_read, &num_descriptors); + for (n = 0; n < num_descriptors; n++) { + AvbDescriptor desc; + + if (!avb_descriptor_validate_and_byteswap(descriptors[n], &desc)) { + avb_errorv(full_partition_name, ": Descriptor is invalid.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + switch (desc.tag) { + case AVB_DESCRIPTOR_TAG_HASH: { + AvbSlotVerifyResult sub_ret; + sub_ret = load_and_verify_hash_partition(ops, + requested_partitions, + ab_suffix, + allow_verification_error, + descriptors[n], + slot_data); + if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { + ret = sub_ret; + if (!allow_verification_error || !result_should_continue(ret)) { + goto out; + } + } + } break; + + case AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: { + AvbSlotVerifyResult sub_ret; + AvbChainPartitionDescriptor chain_desc; + const uint8_t* chain_partition_name; + const uint8_t* chain_public_key; + + /* Only allow CHAIN_PARTITION descriptors in the main vbmeta image. */ + if (!is_main_vbmeta) { + avb_errorv(full_partition_name, + ": Encountered chain descriptor not in main image.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + if (!avb_chain_partition_descriptor_validate_and_byteswap( + (AvbChainPartitionDescriptor*)descriptors[n], &chain_desc)) { + avb_errorv(full_partition_name, + ": Chain partition descriptor is invalid.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + if (chain_desc.rollback_index_location == 0) { + avb_errorv(full_partition_name, + ": Chain partition has invalid " + "rollback_index_location field.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + chain_partition_name = ((const uint8_t*)descriptors[n]) + + sizeof(AvbChainPartitionDescriptor); + chain_public_key = chain_partition_name + chain_desc.partition_name_len; + + sub_ret = load_and_verify_vbmeta(ops, + requested_partitions, + ab_suffix, + allow_verification_error, + toplevel_vbmeta_flags, + chain_desc.rollback_index_location, + (const char*)chain_partition_name, + chain_desc.partition_name_len, + chain_public_key, + chain_desc.public_key_len, + slot_data, + NULL /* out_algorithm_type */); + if (sub_ret != AVB_SLOT_VERIFY_RESULT_OK) { + ret = sub_ret; + if (!result_should_continue(ret)) { + goto out; + } + } + } break; + + case AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: { + const uint8_t* kernel_cmdline; + AvbKernelCmdlineDescriptor kernel_cmdline_desc; + bool apply_cmdline; + + if (!avb_kernel_cmdline_descriptor_validate_and_byteswap( + (AvbKernelCmdlineDescriptor*)descriptors[n], + &kernel_cmdline_desc)) { + avb_errorv(full_partition_name, + ": Kernel cmdline descriptor is invalid.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + kernel_cmdline = ((const uint8_t*)descriptors[n]) + + sizeof(AvbKernelCmdlineDescriptor); + + if (!avb_validate_utf8(kernel_cmdline, + kernel_cmdline_desc.kernel_cmdline_length)) { + avb_errorv(full_partition_name, + ": Kernel cmdline is not valid UTF-8.\n", + NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + /* Compare the flags for top-level VBMeta struct with flags in + * the command-line descriptor so command-line snippets only + * intended for a certain mode (dm-verity enabled/disabled) + * are skipped if applicable. + */ + apply_cmdline = true; + if (toplevel_vbmeta_flags & AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED) { + if (kernel_cmdline_desc.flags & + AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_NOT_DISABLED) { + apply_cmdline = false; + } + } else { + if (kernel_cmdline_desc.flags & + AVB_KERNEL_CMDLINE_FLAGS_USE_ONLY_IF_HASHTREE_DISABLED) { + apply_cmdline = false; + } + } + + if (apply_cmdline) { + if (slot_data->cmdline == NULL) { + slot_data->cmdline = + avb_calloc(kernel_cmdline_desc.kernel_cmdline_length + 1); + if (slot_data->cmdline == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } + avb_memcpy(slot_data->cmdline, + kernel_cmdline, + kernel_cmdline_desc.kernel_cmdline_length); + } else { + /* new cmdline is: <existing_cmdline> + ' ' + <newcmdline> + '\0' */ + size_t orig_size = avb_strlen(slot_data->cmdline); + size_t new_size = + orig_size + 1 + kernel_cmdline_desc.kernel_cmdline_length + 1; + char* new_cmdline = avb_calloc(new_size); + if (new_cmdline == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto out; + } + avb_memcpy(new_cmdline, slot_data->cmdline, orig_size); + new_cmdline[orig_size] = ' '; + avb_memcpy(new_cmdline + orig_size + 1, + kernel_cmdline, + kernel_cmdline_desc.kernel_cmdline_length); + avb_free(slot_data->cmdline); + slot_data->cmdline = new_cmdline; + } + } + } break; + + /* Explicit fall-through */ + case AVB_DESCRIPTOR_TAG_PROPERTY: + case AVB_DESCRIPTOR_TAG_HASHTREE: + /* Do nothing. */ + break; + } + } + + if (rollback_index_location >= AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS) { + avb_errorv( + full_partition_name, ": Invalid rollback_index_location.\n", NULL); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA; + goto out; + } + + slot_data->rollback_indexes[rollback_index_location] = + vbmeta_header.rollback_index; + + if (out_algorithm_type != NULL) { + *out_algorithm_type = (AvbAlgorithmType)vbmeta_header.algorithm_type; + } + +out: + /* If |vbmeta_image_data| isn't NULL it means that it adopted + * |vbmeta_buf| so in that case don't free it here. + */ + if (vbmeta_image_data == NULL) { + if (vbmeta_buf != NULL) { + avb_free(vbmeta_buf); + } + } + if (descriptors != NULL) { + avb_free(descriptors); + } + return ret; +} + +#define NUM_GUIDS 3 + +/* Substitutes all variables (e.g. $(ANDROID_SYSTEM_PARTUUID)) with + * values. Returns NULL on OOM, otherwise the cmdline with values + * replaced. + */ +static char* sub_cmdline(AvbOps* ops, + const char* cmdline, + const char* ab_suffix, + bool using_boot_for_vbmeta) { + const char* part_name_str[NUM_GUIDS] = {"system", "boot", "vbmeta"}; + const char* replace_str[NUM_GUIDS] = {"$(ANDROID_SYSTEM_PARTUUID)", + "$(ANDROID_BOOT_PARTUUID)", + "$(ANDROID_VBMETA_PARTUUID)"}; + char* ret = NULL; + AvbIOResult io_ret; + + /* Special-case for when the top-level vbmeta struct is in the boot + * partition. + */ + if (using_boot_for_vbmeta) { + part_name_str[2] = "boot"; + } + + /* Replace unique partition GUIDs */ + for (size_t n = 0; n < NUM_GUIDS; n++) { + char part_name[PART_NAME_MAX_SIZE]; + char guid_buf[37]; + + if (!avb_str_concat(part_name, + sizeof part_name, + part_name_str[n], + avb_strlen(part_name_str[n]), + ab_suffix, + avb_strlen(ab_suffix))) { + avb_error("Partition name and suffix does not fit.\n"); + goto fail; + } + + io_ret = ops->get_unique_guid_for_partition( + ops, part_name, guid_buf, sizeof guid_buf); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + return NULL; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_error("Error getting unique GUID for partition.\n"); + goto fail; + } + + if (ret == NULL) { + ret = avb_replace(cmdline, replace_str[n], guid_buf); + } else { + char* new_ret = avb_replace(ret, replace_str[n], guid_buf); + avb_free(ret); + ret = new_ret; + } + if (ret == NULL) { + goto fail; + } + } + + return ret; + +fail: + if (ret != NULL) { + avb_free(ret); + } + return NULL; +} + +static int cmdline_append_option(AvbSlotVerifyData* slot_data, + const char* key, + const char* value) { + size_t offset, key_len, value_len; + char* new_cmdline; + + key_len = avb_strlen(key); + value_len = avb_strlen(value); + + offset = 0; + if (slot_data->cmdline != NULL) { + offset = avb_strlen(slot_data->cmdline); + if (offset > 0) { + offset += 1; + } + } + + new_cmdline = avb_calloc(offset + key_len + value_len + 2); + if (new_cmdline == NULL) { + return 0; + } + if (offset > 0) { + avb_memcpy(new_cmdline, slot_data->cmdline, offset - 1); + new_cmdline[offset - 1] = ' '; + } + avb_memcpy(new_cmdline + offset, key, key_len); + new_cmdline[offset + key_len] = '='; + avb_memcpy(new_cmdline + offset + key_len + 1, value, value_len); + if (slot_data->cmdline != NULL) { + avb_free(slot_data->cmdline); + } + slot_data->cmdline = new_cmdline; + + return 1; +} + +#define AVB_MAX_DIGITS_UINT64 32 + +/* Writes |value| to |digits| in base 10 followed by a NUL byte. + * Returns number of characters written excluding the NUL byte. + */ +static size_t uint64_to_base10(uint64_t value, + char digits[AVB_MAX_DIGITS_UINT64]) { + char rev_digits[AVB_MAX_DIGITS_UINT64]; + size_t n, num_digits; + + for (num_digits = 0; num_digits < AVB_MAX_DIGITS_UINT64 - 1;) { + rev_digits[num_digits++] = (value % 10) + '0'; + value /= 10; + if (value == 0) { + break; + } + } + + for (n = 0; n < num_digits; n++) { + digits[n] = rev_digits[num_digits - 1 - n]; + } + digits[n] = '\0'; + return n; +} + +static int cmdline_append_version(AvbSlotVerifyData* slot_data, + const char* key, + uint64_t major_version, + uint64_t minor_version) { + char major_digits[AVB_MAX_DIGITS_UINT64]; + char minor_digits[AVB_MAX_DIGITS_UINT64]; + char combined[AVB_MAX_DIGITS_UINT64 * 2 + 1]; + size_t num_major_digits, num_minor_digits; + + num_major_digits = uint64_to_base10(major_version, major_digits); + num_minor_digits = uint64_to_base10(minor_version, minor_digits); + avb_memcpy(combined, major_digits, num_major_digits); + combined[num_major_digits] = '.'; + avb_memcpy(combined + num_major_digits + 1, minor_digits, num_minor_digits); + combined[num_major_digits + 1 + num_minor_digits] = '\0'; + + return cmdline_append_option(slot_data, key, combined); +} + +static int cmdline_append_uint64_base10(AvbSlotVerifyData* slot_data, + const char* key, + uint64_t value) { + char digits[AVB_MAX_DIGITS_UINT64]; + uint64_to_base10(value, digits); + return cmdline_append_option(slot_data, key, digits); +} + +static int cmdline_append_hex(AvbSlotVerifyData* slot_data, + const char* key, + const uint8_t* data, + size_t data_len) { + char hex_digits[17] = "0123456789abcdef"; + char* hex_data; + int ret; + size_t n; + + hex_data = avb_malloc(data_len * 2 + 1); + if (hex_data == NULL) { + return 0; + } + + for (n = 0; n < data_len; n++) { + hex_data[n * 2] = hex_digits[data[n] >> 4]; + hex_data[n * 2 + 1] = hex_digits[data[n] & 0x0f]; + } + hex_data[n * 2] = '\0'; + + ret = cmdline_append_option(slot_data, key, hex_data); + avb_free(hex_data); + return ret; +} + +AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, + const char* const* requested_partitions, + const char* ab_suffix, + bool allow_verification_error, + AvbSlotVerifyData** out_data) { + AvbSlotVerifyResult ret; + AvbSlotVerifyData* slot_data = NULL; + AvbAlgorithmType algorithm_type = AVB_ALGORITHM_TYPE_NONE; + AvbIOResult io_ret; + bool using_boot_for_vbmeta = false; + + if (out_data != NULL) { + *out_data = NULL; + } + + slot_data = avb_calloc(sizeof(AvbSlotVerifyData)); + if (slot_data == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + slot_data->vbmeta_images = + avb_calloc(sizeof(AvbVBMetaData) * MAX_NUMBER_OF_VBMETA_IMAGES); + if (slot_data->vbmeta_images == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + slot_data->loaded_partitions = + avb_calloc(sizeof(AvbPartitionData) * MAX_NUMBER_OF_LOADED_PARTITIONS); + if (slot_data->loaded_partitions == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + + ret = load_and_verify_vbmeta(ops, + requested_partitions, + ab_suffix, + allow_verification_error, + 0 /* toplevel_vbmeta_flags */, + 0 /* rollback_index_location */, + "vbmeta", + avb_strlen("vbmeta"), + NULL /* expected_public_key */, + 0 /* expected_public_key_length */, + slot_data, + &algorithm_type); + if (!allow_verification_error && ret != AVB_SLOT_VERIFY_RESULT_OK) { + goto fail; + } + + if (avb_strcmp(slot_data->vbmeta_images[0].partition_name, "vbmeta") != 0) { + avb_assert(avb_strcmp(slot_data->vbmeta_images[0].partition_name, "boot") == + 0); + using_boot_for_vbmeta = true; + } + + /* If things check out, mangle the kernel command-line as needed. */ + if (result_should_continue(ret)) { + /* Fill in |ab_suffix| field. */ + slot_data->ab_suffix = avb_strdup(ab_suffix); + if (slot_data->ab_suffix == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + + /* Add androidboot.vbmeta.device option. */ + if (!cmdline_append_option(slot_data, + "androidboot.vbmeta.device", + "PARTUUID=$(ANDROID_VBMETA_PARTUUID)")) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + + /* Add androidboot.vbmeta.avb_version option. */ + if (!cmdline_append_version(slot_data, + "androidboot.vbmeta.avb_version", + AVB_VERSION_MAJOR, + AVB_VERSION_MINOR)) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + + /* Substitute $(ANDROID_SYSTEM_PARTUUID) and friends. */ + if (slot_data->cmdline != NULL) { + char* new_cmdline; + new_cmdline = sub_cmdline( + ops, slot_data->cmdline, ab_suffix, using_boot_for_vbmeta); + if (new_cmdline == NULL) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + avb_free(slot_data->cmdline); + slot_data->cmdline = new_cmdline; + } + + /* Set androidboot.avb.device_state to "locked" or "unlocked". */ + bool is_device_unlocked; + io_ret = ops->read_is_device_unlocked(ops, &is_device_unlocked); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } else if (io_ret != AVB_IO_RESULT_OK) { + avb_error("Error getting device state.\n"); + ret = AVB_SLOT_VERIFY_RESULT_ERROR_IO; + goto fail; + } + if (!cmdline_append_option(slot_data, + "androidboot.vbmeta.device_state", + is_device_unlocked ? "unlocked" : "locked")) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + + /* Set androidboot.vbmeta.{hash_alg, size, digest} - use same hash + * function as is used to sign vbmeta. + */ + switch (algorithm_type) { + /* Explicit fallthrough. */ + case AVB_ALGORITHM_TYPE_NONE: + case AVB_ALGORITHM_TYPE_SHA256_RSA2048: + case AVB_ALGORITHM_TYPE_SHA256_RSA4096: + case AVB_ALGORITHM_TYPE_SHA256_RSA8192: { + AvbSHA256Ctx ctx; + size_t n, total_size = 0; + avb_sha256_init(&ctx); + for (n = 0; n < slot_data->num_vbmeta_images; n++) { + avb_sha256_update(&ctx, + slot_data->vbmeta_images[n].vbmeta_data, + slot_data->vbmeta_images[n].vbmeta_size); + total_size += slot_data->vbmeta_images[n].vbmeta_size; + } + if (!cmdline_append_option( + slot_data, "androidboot.vbmeta.hash_alg", "sha256") || + !cmdline_append_uint64_base10( + slot_data, "androidboot.vbmeta.size", total_size) || + !cmdline_append_hex(slot_data, + "androidboot.vbmeta.digest", + avb_sha256_final(&ctx), + AVB_SHA256_DIGEST_SIZE)) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + } break; + /* Explicit fallthrough. */ + case AVB_ALGORITHM_TYPE_SHA512_RSA2048: + case AVB_ALGORITHM_TYPE_SHA512_RSA4096: + case AVB_ALGORITHM_TYPE_SHA512_RSA8192: { + AvbSHA512Ctx ctx; + size_t n, total_size = 0; + avb_sha512_init(&ctx); + for (n = 0; n < slot_data->num_vbmeta_images; n++) { + avb_sha512_update(&ctx, + slot_data->vbmeta_images[n].vbmeta_data, + slot_data->vbmeta_images[n].vbmeta_size); + total_size += slot_data->vbmeta_images[n].vbmeta_size; + } + if (!cmdline_append_option( + slot_data, "androidboot.vbmeta.hash_alg", "sha512") || + !cmdline_append_uint64_base10( + slot_data, "androidboot.vbmeta.size", total_size) || + !cmdline_append_hex(slot_data, + "androidboot.vbmeta.digest", + avb_sha512_final(&ctx), + AVB_SHA512_DIGEST_SIZE)) { + ret = AVB_SLOT_VERIFY_RESULT_ERROR_OOM; + goto fail; + } + } break; + case _AVB_ALGORITHM_NUM_TYPES: + avb_assert_not_reached(); + break; + } + + if (out_data != NULL) { + *out_data = slot_data; + } else { + avb_slot_verify_data_free(slot_data); + } + } + + if (!allow_verification_error) { + avb_assert(ret == AVB_SLOT_VERIFY_RESULT_OK); + } + + return ret; + +fail: + if (slot_data != NULL) { + avb_slot_verify_data_free(slot_data); + } + return ret; +} + +void avb_slot_verify_data_free(AvbSlotVerifyData* data) { + if (data->ab_suffix != NULL) { + avb_free(data->ab_suffix); + } + if (data->cmdline != NULL) { + avb_free(data->cmdline); + } + if (data->vbmeta_images != NULL) { + size_t n; + for (n = 0; n < data->num_vbmeta_images; n++) { + AvbVBMetaData* vbmeta_image = &data->vbmeta_images[n]; + if (vbmeta_image->partition_name != NULL) { + avb_free(vbmeta_image->partition_name); + } + if (vbmeta_image->vbmeta_data != NULL) { + avb_free(vbmeta_image->vbmeta_data); + } + } + avb_free(data->vbmeta_images); + } + if (data->loaded_partitions != NULL) { + size_t n; + for (n = 0; n < data->num_loaded_partitions; n++) { + AvbPartitionData* loaded_partition = &data->loaded_partitions[n]; + if (loaded_partition->partition_name != NULL) { + avb_free(loaded_partition->partition_name); + } + if (loaded_partition->data != NULL) { + avb_free(loaded_partition->data); + } + } + avb_free(data->loaded_partitions); + } + avb_free(data); +} + +const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result) { + const char* ret = NULL; + + switch (result) { + case AVB_SLOT_VERIFY_RESULT_OK: + ret = "OK"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: + ret = "ERROR_OOM"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_IO: + ret = "ERROR_IO"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: + ret = "ERROR_VERIFICATION"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: + ret = "ERROR_ROLLBACK_INDEX"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: + ret = "ERROR_PUBLIC_KEY_REJECTED"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: + ret = "ERROR_INVALID_METADATA"; + break; + case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: + ret = "ERROR_UNSUPPORTED_VERSION"; + break; + /* Do not add a 'default:' case here because of -Wswitch. */ + } + + if (ret == NULL) { + avb_error("Unknown AvbSlotVerifyResult value.\n"); + ret = "(unknown)"; + } + + return ret; +} diff --git a/libavb/avb_slot_verify.h b/libavb/avb_slot_verify.h new file mode 100644 index 0000000..08b11fc --- a/dev/null +++ b/libavb/avb_slot_verify.h @@ -0,0 +1,257 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_SLOT_VERIFY_H_ +#define AVB_SLOT_VERIFY_H_ + +#include "avb_ops.h" +#include "avb_vbmeta_image.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Return codes used in avb_slot_verify(), see that function for + * documentation for each field. + * + * Use avb_slot_verify_result_to_string() to get a textual + * representation usable for error/debug output. + */ +typedef enum { + AVB_SLOT_VERIFY_RESULT_OK, + AVB_SLOT_VERIFY_RESULT_ERROR_OOM, + AVB_SLOT_VERIFY_RESULT_ERROR_IO, + AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, + AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX, + AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED, + AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA, + AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION +} AvbSlotVerifyResult; + +/* Get a textual representation of |result|. */ +const char* avb_slot_verify_result_to_string(AvbSlotVerifyResult result); + +/* Maximum number of rollback index locations supported. */ +#define AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS 32 + +/* AvbPartitionData contains data loaded from partitions when using + * avb_slot_verify(). The |partition_name| field contains the name of + * the partition (without A/B suffix), |data| points to the loaded + * data which is |data_size| bytes long. + * + * Note that this is strictly less than the partition size - it's only + * the image stored there, not the entire partition nor any of the + * metadata. + */ +typedef struct { + char* partition_name; + uint8_t* data; + size_t data_size; +} AvbPartitionData; + +/* AvbVBMetaData contains a vbmeta struct loaded from a partition when + * using avb_slot_verify(). The |partition_name| field contains the + * name of the partition (without A/B suffix), |vbmeta_data| points to + * the loaded data which is |vbmeta_size| bytes long. + * + * The |verify_result| field contains the result of + * avb_vbmeta_image_verify() on the data. This is guaranteed to be + * AVB_VBMETA_VERIFY_RESULT_OK for all vbmeta images if + * avb_slot_verify() returns AVB_SLOT_VERIFY_RESULT_OK. + * + * You can use avb_descriptor_get_all(), avb_descriptor_foreach(), and + * avb_vbmeta_image_header_to_host_byte_order() with this data. + */ +typedef struct { + char* partition_name; + uint8_t* vbmeta_data; + size_t vbmeta_size; + AvbVBMetaVerifyResult verify_result; +} AvbVBMetaData; + +/* AvbSlotVerifyData contains data needed to boot a particular slot + * and is returned by avb_slot_verify() if partitions in a slot are + * successfully verified. + * + * All data pointed to by this struct - including data in each item in + * the |partitions| array - will be freed when the + * avb_slot_verify_data_free() function is called. + * + * The |ab_suffix| field is the copy of the of |ab_suffix| field + * passed to avb_slot_verify(). It is the A/B suffix of the slot. + * + * The VBMeta images that were checked are available in the + * |vbmeta_images| field. The field |num_vbmeta_images| contains the + * number of elements in this array. The first element - + * vbmeta_images[0] - is guaranteed to be from the partition with the + * top-level vbmeta struct. This is usually the "vbmeta" partition in + * the requested slot but if there is no "vbmeta" partition it can + * also be the "boot" partition. + * + * The partitions loaded and verified from from the slot are + * accessible in the |loaded_partitions| array. The field + * |num_loaded_partitions| contains the number of elements in this + * array. The order of partitions in this array may not necessarily be + * the same order as in the passed-in |requested_partitions| array. + * + * Rollback indexes for the verified slot are stored in the + * |rollback_indexes| field. Note that avb_slot_verify() will NEVER + * modify stored_rollback_index[n] locations e.g. it will never use + * the write_rollback_index() AvbOps operation. Instead it is the job + * of the caller of avb_slot_verify() to do this based on e.g. A/B + * policy and other factors. See libavb_ab/avb_ab_flow.c for an + * example of how to do this. + * + * The |cmdline| field is a NUL-terminated string in UTF-8 resulting + * from concatenating all |AvbKernelCmdlineDescriptor| and then + * performing proper substitution of the variables + * $(ANDROID_SYSTEM_PARTUUID), $(ANDROID_BOOT_PARTUUID), and + * $(ANDROID_VBMETA_PARTUUID) using the + * get_unique_guid_for_partition() operation in |AvbOps|. + * + * Additionally, the |cmdline| field will have the following kernel + * command-line options set: + * + * androidboot.vbmeta.device_state: set to "locked" or "unlocked" + * depending on the result of the result of AvbOps's + * read_is_unlocked() function. + * + * androidboot.vbmeta.{hash_alg, size, digest}: Will be set to + * the digest of all images in |vbmeta_images|. + * + * androidboot.vbmeta.device: This is set to the value + * PARTUUID=$(ANDROID_VBMETA_PARTUUID) before substitution so it + * will end up pointing to the vbmeta partition for the verified + * slot. If there is no vbmeta partition it will point to the boot + * partition of the verified slot. + * + * androidboot.vbmeta.avb_version: This is set to the decimal value + * of AVB_VERSION_MAJOR followed by a dot followed by the decimal + * value of AVB_VERSION_MINOR, for example "1.0" or "1.4". This + * version number represents the vbmeta file format version + * supported by libavb copy used in the boot loader. This is not + * necessarily the same version number of the on-disk metadata for + * the slot that was verified. + * + * Note that androidboot.slot_suffix is not set in |cmdline| - you + * will have to pass this command-line option yourself. + * + * This struct may grow in the future without it being considered an + * ABI break. + */ +typedef struct { + char* ab_suffix; + AvbVBMetaData* vbmeta_images; + size_t num_vbmeta_images; + AvbPartitionData* loaded_partitions; + size_t num_loaded_partitions; + char* cmdline; + uint64_t rollback_indexes[AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS]; +} AvbSlotVerifyData; + +/* Frees a |AvbSlotVerifyData| including all data it points to. */ +void avb_slot_verify_data_free(AvbSlotVerifyData* data); + +/* Performs a full verification of the slot identified by |ab_suffix| + * and load the contents of the partitions whose name is in the + * NULL-terminated string array |requested_partitions| (each partition + * must use hash verification). If not using A/B, pass an empty string + * (e.g. "", not NULL) for |ab_suffix|. + * + * Typically the |requested_partitions| array only contains a single + * item for the boot partition, 'boot'. + * + * Verification includes loading data from the 'vbmeta', all hash + * partitions, and possibly other partitions (with |ab_suffix| + * appended), inspecting rollback indexes, and checking if the public + * key used to sign the data is acceptable. The functions in |ops| + * will be used to do this. + * + * If |out_data| is not NULL, it will be set to a newly allocated + * |AvbSlotVerifyData| struct containing all the data needed to + * actually boot the slot. This data structure should be freed with + * avb_slot_verify_data_free() when you are done with it. See below + * for when this is returned. + * + * If |allow_verification_error| is false this function will bail out + * as soon as an error is encountered and |out_data| is set only if + * AVB_SLOT_VERIFY_RESULT_OK is returned. + * + * Otherwise if |allow_verification_error| is true the function will + * continue verification efforts and |out_data| is also set if + * AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED, + * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, or + * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned. It is + * undefined which error is returned if more than one distinct error + * is encountered. It is guaranteed that AVB_SLOT_VERIFY_RESULT_OK is + * returned if, and only if, there are no errors. This mode is needed + * to boot valid but unverified slots when the device is unlocked. + * + * Also note that |out_data| is never set if + * AVB_SLOT_VERIFY_RESULT_ERROR_OOM, AVB_SLOT_VERIFY_RESULT_ERROR_IO, + * or AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned. + * + * AVB_SLOT_VERIFY_RESULT_OK is returned if everything is verified + * correctly and all public keys are accepted. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED is returned if + * everything is verified correctly out but one or more public keys + * are not accepted. This includes the case where integrity data is + * not signed. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_OOM is returned if unable to + * allocate memory. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_IO is returned if an I/O error + * occurred while trying to load data or get a rollback index. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION is returned if the data + * did not verify, e.g. the digest didn't match or signature checks + * failed. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX is returned if a + * rollback index was less than its stored value. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA is returned if some + * of the metadata is invalid or inconsistent. + * + * AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION is returned if + * some of the metadata requires a newer version of libavb than what + * is in use. + */ +AvbSlotVerifyResult avb_slot_verify(AvbOps* ops, + const char* const* requested_partitions, + const char* ab_suffix, + bool allow_verification_error, + AvbSlotVerifyData** out_data); + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_SLOT_VERIFY_H_ */ diff --git a/libavb/avb_sysdeps.h b/libavb/avb_sysdeps.h new file mode 100644 index 0000000..aea837a --- a/dev/null +++ b/libavb/avb_sysdeps.h @@ -0,0 +1,118 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_SYSDEPS_H_ +#define AVB_SYSDEPS_H_ + +#ifdef __cplusplus +extern "C" { +#endif + +/* Change these includes to match your platform to bring in the + * equivalent types available in a normal C runtime. At least things + * like uint8_t, uint64_t, and bool (with |false|, |true| keywords) + * must be present. + */ +#include <inttypes.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdint.h> + +/* If you don't have gcc or clang, these attribute macros may need to + * be adjusted. + */ +#define AVB_ATTR_WARN_UNUSED_RESULT __attribute__((warn_unused_result)) +#define AVB_ATTR_PACKED __attribute__((packed)) +#define AVB_ATTR_NO_RETURN __attribute__((noreturn)) +#define AVB_ATTR_SENTINEL __attribute__((__sentinel__)) + +/* Size in bytes used for alignment. */ +#ifdef __LP64__ +#define AVB_ALIGNMENT_SIZE 8 +#else +#define AVB_ALIGNMENT_SIZE 4 +#endif + +/* Compare |n| bytes in |src1| and |src2|. + * + * Returns an integer less than, equal to, or greater than zero if the + * first |n| bytes of |src1| is found, respectively, to be less than, + * to match, or be greater than the first |n| bytes of |src2|. */ +int avb_memcmp(const void* src1, + const void* src2, + size_t n) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Compare two strings. + * + * Return an integer less than, equal to, or greater than zero if |s1| + * is found, respectively, to be less than, to match, or be greater + * than |s2|. + */ +int avb_strcmp(const char* s1, const char* s2); + +/* Copy |n| bytes from |src| to |dest|. */ +void* avb_memcpy(void* dest, const void* src, size_t n); + +/* Set |n| bytes starting at |s| to |c|. Returns |dest|. */ +void* avb_memset(void* dest, const int c, size_t n); + +/* Prints out a message. The string passed must be a NUL-terminated + * UTF-8 string. + */ +void avb_print(const char* message); + +/* Prints out a vector of strings. Each argument must point to a + * NUL-terminated UTF-8 string and NULL should be the last argument. + */ +void avb_printv(const char* message, ...) AVB_ATTR_SENTINEL; + +/* Aborts the program or reboots the device. */ +void avb_abort(void) AVB_ATTR_NO_RETURN; + +/* Allocates |size| bytes. Returns NULL if no memory is available, + * otherwise a pointer to the allocated memory. + * + * The memory is not initialized. + * + * The pointer returned is guaranteed to be word-aligned. + * + * The memory should be freed with avb_free() when you are done with it. + */ +void* avb_malloc_(size_t size) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Frees memory previously allocated with avb_malloc(). */ +void avb_free(void* ptr); + +/* Returns the lenght of |str|, excluding the terminating NUL-byte. */ +size_t avb_strlen(const char* str) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_SYSDEPS_H_ */ diff --git a/libavb/avb_sysdeps_posix.c b/libavb/avb_sysdeps_posix.c new file mode 100644 index 0000000..25f4656 --- a/dev/null +++ b/libavb/avb_sysdeps_posix.c @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#define LOG_TAG "control_avb" + +#include <log/log.h> + +#include <endian.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "avb_sysdeps.h" + +int avb_memcmp(const void* src1, const void* src2, size_t n) { + return memcmp(src1, src2, n); +} + +void* avb_memcpy(void* dest, const void* src, size_t n) { + return memcpy(dest, src, n); +} + +void* avb_memset(void* dest, const int c, size_t n) { + return memset(dest, c, n); +} + +int avb_strcmp(const char* s1, const char* s2) { + return strcmp(s1, s2); +} + +size_t avb_strlen(const char* str) { + return strlen(str); +} + +void avb_abort(void) { + ALOGE("********come to avb_abort"); + abort(); +} + +void avb_print(const char* message) { + fprintf(stderr, "%s", message); + ALOGE("********avb_print: %s", message); +} + +void avb_printv(const char* message, ...) { + va_list ap; + const char* m; + + va_start(ap, message); + for (m = message; m != NULL; m = va_arg(ap, const char*)) { + ALOGE("********avb_printv: %s", m); + fprintf(stderr, "%s", m); + } + va_end(ap); +} + +void* avb_malloc_(size_t size) { + return malloc(size); +} + +void avb_free(void* ptr) { + free(ptr); +} diff --git a/libavb/avb_util.c b/libavb/avb_util.c new file mode 100644 index 0000000..43662b4 --- a/dev/null +++ b/libavb/avb_util.c @@ -0,0 +1,403 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_util.h" + +#include <stdarg.h> + +uint32_t avb_be32toh(uint32_t in) { + uint8_t* d = (uint8_t*)∈ + uint32_t ret; + ret = ((uint32_t)d[0]) << 24; + ret |= ((uint32_t)d[1]) << 16; + ret |= ((uint32_t)d[2]) << 8; + ret |= ((uint32_t)d[3]); + return ret; +} + +uint64_t avb_be64toh(uint64_t in) { + uint8_t* d = (uint8_t*)∈ + uint64_t ret; + ret = ((uint64_t)d[0]) << 56; + ret |= ((uint64_t)d[1]) << 48; + ret |= ((uint64_t)d[2]) << 40; + ret |= ((uint64_t)d[3]) << 32; + ret |= ((uint64_t)d[4]) << 24; + ret |= ((uint64_t)d[5]) << 16; + ret |= ((uint64_t)d[6]) << 8; + ret |= ((uint64_t)d[7]); + return ret; +} + +/* Converts a 32-bit unsigned integer from host to big-endian byte order. */ +uint32_t avb_htobe32(uint32_t in) { + union { + uint32_t word; + uint8_t bytes[4]; + } ret; + ret.bytes[0] = (in >> 24) & 0xff; + ret.bytes[1] = (in >> 16) & 0xff; + ret.bytes[2] = (in >> 8) & 0xff; + ret.bytes[3] = in & 0xff; + return ret.word; +} + +/* Converts a 64-bit unsigned integer from host to big-endian byte order. */ +uint64_t avb_htobe64(uint64_t in) { + union { + uint64_t word; + uint8_t bytes[8]; + } ret; + ret.bytes[0] = (in >> 56) & 0xff; + ret.bytes[1] = (in >> 48) & 0xff; + ret.bytes[2] = (in >> 40) & 0xff; + ret.bytes[3] = (in >> 32) & 0xff; + ret.bytes[4] = (in >> 24) & 0xff; + ret.bytes[5] = (in >> 16) & 0xff; + ret.bytes[6] = (in >> 8) & 0xff; + ret.bytes[7] = in & 0xff; + return ret.word; +} + +int avb_safe_memcmp(const void* s1, const void* s2, size_t n) { + const unsigned char* us1 = s1; + const unsigned char* us2 = s2; + int result = 0; + + if (0 == n) { + return 0; + } + + /* + * Code snippet without data-dependent branch due to Nate Lawson + * (nate@root.org) of Root Labs. + */ + while (n--) { + result |= *us1++ ^ *us2++; + } + + return result != 0; +} + +bool avb_safe_add_to(uint64_t* value, uint64_t value_to_add) { + uint64_t original_value; + + avb_assert(value != NULL); + + original_value = *value; + + *value += value_to_add; + if (*value < original_value) { + avb_error("Overflow when adding values.\n"); + return false; + } + + return true; +} + +bool avb_safe_add(uint64_t* out_result, uint64_t a, uint64_t b) { + uint64_t dummy; + if (out_result == NULL) { + out_result = &dummy; + } + *out_result = a; + return avb_safe_add_to(out_result, b); +} + +bool avb_validate_utf8(const uint8_t* data, size_t num_bytes) { + size_t n; + unsigned int num_cc; + + for (n = 0, num_cc = 0; n < num_bytes; n++) { + uint8_t c = data[n]; + + if (num_cc > 0) { + if ((c & (0x80 | 0x40)) == 0x80) { + /* 10xx xxxx */ + } else { + goto fail; + } + num_cc--; + } else { + if (c < 0x80) { + num_cc = 0; + } else if ((c & (0x80 | 0x40 | 0x20)) == (0x80 | 0x40)) { + /* 110x xxxx */ + num_cc = 1; + } else if ((c & (0x80 | 0x40 | 0x20 | 0x10)) == (0x80 | 0x40 | 0x20)) { + /* 1110 xxxx */ + num_cc = 2; + } else if ((c & (0x80 | 0x40 | 0x20 | 0x10 | 0x08)) == + (0x80 | 0x40 | 0x20 | 0x10)) { + /* 1111 0xxx */ + num_cc = 3; + } else { + goto fail; + } + } + } + + if (num_cc != 0) { + goto fail; + } + + return true; + +fail: + return false; +} + +bool avb_str_concat(char* buf, + size_t buf_size, + const char* str1, + size_t str1_len, + const char* str2, + size_t str2_len) { + uint64_t combined_len; + + if (!avb_safe_add(&combined_len, str1_len, str2_len)) { + avb_error("Overflow when adding string sizes.\n"); + return false; + } + + if (combined_len > buf_size - 1) { + avb_error("Insufficient buffer space.\n"); + return false; + } + + avb_memcpy(buf, str1, str1_len); + avb_memcpy(buf + str1_len, str2, str2_len); + buf[combined_len] = '\0'; + + return true; +} + +void* avb_malloc(size_t size) { + void* ret = avb_malloc_(size); + if (ret == NULL) { + avb_error("Failed to allocate memory.\n"); + return NULL; + } + return ret; +} + +void* avb_calloc(size_t size) { + void* ret = avb_malloc(size); + if (ret == NULL) { + return NULL; + } + + avb_memset(ret, '\0', size); + return ret; +} + +char* avb_strdup(const char* str) { + size_t len = avb_strlen(str); + char* ret = avb_malloc(len + 1); + if (ret == NULL) { + return NULL; + } + + avb_memcpy(ret, str, len); + ret[len] = '\0'; + + return ret; +} + +const char* avb_strstr(const char* haystack, const char* needle) { + size_t n, m; + + /* Look through |haystack| and check if the first character of + * |needle| matches. If so, check the rest of |needle|. + */ + for (n = 0; haystack[n] != '\0'; n++) { + if (haystack[n] != needle[0]) { + continue; + } + + for (m = 1;; m++) { + if (needle[m] == '\0') { + return haystack + n; + } + + if (haystack[n + m] != needle[m]) { + break; + } + } + } + + return NULL; +} + +const char* avb_strv_find_str(const char* const* strings, + const char* str, + size_t str_size) { + size_t n; + for (n = 0; strings[n] != NULL; n++) { + if (avb_strlen(strings[n]) == str_size && + avb_memcmp(strings[n], str, str_size) == 0) { + return strings[n]; + } + } + return NULL; +} + +char* avb_replace(const char* str, const char* search, const char* replace) { + char* ret = NULL; + size_t ret_len = 0; + size_t search_len, replace_len; + const char* str_after_last_replace; + + search_len = avb_strlen(search); + replace_len = avb_strlen(replace); + + str_after_last_replace = str; + while (*str != '\0') { + const char* s; + size_t num_before; + size_t num_new; + + s = avb_strstr(str, search); + if (s == NULL) { + break; + } + + num_before = s - str; + + if (ret == NULL) { + num_new = num_before + replace_len + 1; + ret = avb_malloc(num_new); + if (ret == NULL) { + goto out; + } + avb_memcpy(ret, str, num_before); + avb_memcpy(ret + num_before, replace, replace_len); + ret[num_new - 1] = '\0'; + ret_len = num_new - 1; + } else { + char* new_str; + num_new = ret_len + num_before + replace_len + 1; + new_str = avb_malloc(num_new); + if (ret == NULL) { + goto out; + } + avb_memcpy(new_str, ret, ret_len); + avb_memcpy(new_str + ret_len, str, num_before); + avb_memcpy(new_str + ret_len + num_before, replace, replace_len); + new_str[num_new - 1] = '\0'; + avb_free(ret); + ret = new_str; + ret_len = num_new - 1; + } + + str = s + search_len; + str_after_last_replace = str; + } + + if (ret == NULL) { + ret = avb_strdup(str_after_last_replace); + if (ret == NULL) { + goto out; + } + } else { + size_t num_remaining = avb_strlen(str_after_last_replace); + size_t num_new = ret_len + num_remaining + 1; + char* new_str = avb_malloc(num_new); + if (ret == NULL) { + goto out; + } + avb_memcpy(new_str, ret, ret_len); + avb_memcpy(new_str + ret_len, str_after_last_replace, num_remaining); + new_str[num_new - 1] = '\0'; + avb_free(ret); + ret = new_str; + ret_len = num_new - 1; + } + +out: + return ret; +} + +/* We only support a limited amount of strings in avb_strdupv(). */ +#define AVB_STRDUPV_MAX_NUM_STRINGS 32 + +char* avb_strdupv(const char* str, ...) { + va_list ap; + const char* strings[AVB_STRDUPV_MAX_NUM_STRINGS]; + size_t lengths[AVB_STRDUPV_MAX_NUM_STRINGS]; + size_t num_strings, n; + uint64_t total_length; + char *ret = NULL, *dest; + + num_strings = 0; + total_length = 0; + va_start(ap, str); + do { + size_t str_len = avb_strlen(str); + strings[num_strings] = str; + lengths[num_strings] = str_len; + if (!avb_safe_add_to(&total_length, str_len)) { + avb_fatal("Overflow while determining total length.\n"); + break; + } + num_strings++; + if (num_strings == AVB_STRDUPV_MAX_NUM_STRINGS) { + avb_fatal("Too many strings passed.\n"); + break; + } + str = va_arg(ap, const char*); + } while (str != NULL); + va_end(ap); + + ret = avb_malloc(total_length + 1); + if (ret == NULL) { + goto out; + } + + dest = ret; + for (n = 0; n < num_strings; n++) { + avb_memcpy(dest, strings[n], lengths[n]); + dest += lengths[n]; + } + *dest = '\0'; + avb_assert(dest == ret + total_length); + +out: + return ret; +} + +const char* avb_basename(const char* str) { + int64_t n; + size_t len; + + len = avb_strlen(str); + if (len >= 2) { + for (n = len - 2; n >= 0; n--) { + if (str[n] == '/') { + return str + n + 1; + } + } + } + return str; +} diff --git a/libavb/avb_util.h b/libavb/avb_util.h new file mode 100644 index 0000000..07c3258 --- a/dev/null +++ b/libavb/avb_util.h @@ -0,0 +1,277 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_UTIL_H_ +#define AVB_UTIL_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#define AVB_STRINGIFY(x) #x +#define AVB_TO_STRING(x) AVB_STRINGIFY(x) + +#ifdef AVB_ENABLE_DEBUG +/* Aborts the program if |expr| is false. + * + * This has no effect unless AVB_ENABLE_DEBUG is defined. + */ +#define avb_assert(expr) \ + do { \ + if (!(expr)) { \ + avb_fatal("assert fail: " #expr "\n"); \ + } \ + } while (0) +#else +#define avb_assert(expr) +#endif + +/* Aborts the program if reached. + * + * This has no effect unless AVB_ENABLE_DEBUG is defined. + */ +#ifdef AVB_ENABLE_DEBUG +#define avb_assert_not_reached() \ + do { \ + avb_fatal("assert_not_reached()\n"); \ + } while (0) +#else +#define avb_assert_not_reached() +#endif + +/* Aborts the program if |addr| is not word-aligned. + * + * This has no effect unless AVB_ENABLE_DEBUG is defined. + */ +#define avb_assert_aligned(addr) \ + avb_assert((((uintptr_t)addr) & (AVB_ALIGNMENT_SIZE - 1)) == 0) + +#ifdef AVB_ENABLE_DEBUG +/* Print functions, used for diagnostics. + * + * These have no effect unless AVB_ENABLE_DEBUG is defined. + */ +#define avb_debug(message) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": DEBUG: ", \ + message, \ + NULL); \ + } while (0) +#define avb_debugv(message, ...) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": DEBUG: ", \ + message, \ + ##__VA_ARGS__); \ + } while (0) +#else +#define avb_debug(message) +#define avb_debugv(message, ...) +#endif + +/* Prints out a message. This is typically used if a runtime-error + * occurs. + */ +#define avb_error(message) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": ERROR: ", \ + message, \ + NULL); \ + } while (0) +#define avb_errorv(message, ...) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": ERROR: ", \ + message, \ + ##__VA_ARGS__); \ + } while (0) + +/* Prints out a message and calls avb_abort(). + */ +#define avb_fatal(message) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": FATAL: ", \ + message, \ + NULL); \ + avb_abort(); \ + } while (0) +#define avb_fatalv(message, ...) \ + do { \ + avb_printv(avb_basename(__FILE__), \ + ":", \ + AVB_TO_STRING(__LINE__), \ + ": FATAL: ", \ + message, \ + ##__VA_ARGS__); \ + avb_abort(); \ + } while (0) + +/* Converts a 32-bit unsigned integer from big-endian to host byte order. */ +uint32_t avb_be32toh(uint32_t in) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Converts a 64-bit unsigned integer from big-endian to host byte order. */ +uint64_t avb_be64toh(uint64_t in) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Converts a 32-bit unsigned integer from host to big-endian byte order. */ +uint32_t avb_htobe32(uint32_t in) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Converts a 64-bit unsigned integer from host to big-endian byte order. */ +uint64_t avb_htobe64(uint64_t in) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Compare |n| bytes starting at |s1| with |s2| and return 0 if they + * match, 1 if they don't. Returns 0 if |n|==0, since no bytes + * mismatched. + * + * Time taken to perform the comparison is only dependent on |n| and + * not on the relationship of the match between |s1| and |s2|. + * + * Note that unlike avb_memcmp(), this only indicates inequality, not + * whether |s1| is less than or greater than |s2|. + */ +int avb_safe_memcmp(const void* s1, + const void* s2, + size_t n) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Adds |value_to_add| to |value| with overflow protection. + * + * Returns false if the addition overflows, true otherwise. In either + * case, |value| is always modified. + */ +bool avb_safe_add_to(uint64_t* value, + uint64_t value_to_add) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Adds |a| and |b| with overflow protection, returning the value in + * |out_result|. + * + * It's permissible to pass NULL for |out_result| if you just want to + * check that the addition would not overflow. + * + * Returns false if the addition overflows, true otherwise. + */ +bool avb_safe_add(uint64_t* out_result, + uint64_t a, + uint64_t b) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Checks if |num_bytes| data at |data| is a valid UTF-8 + * string. Returns true if valid UTF-8, false otherwise. + */ +bool avb_validate_utf8(const uint8_t* data, + size_t num_bytes) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Concatenates |str1| (of |str1_len| bytes) and |str2| (of |str2_len| + * bytes) and puts the result in |buf| which holds |buf_size| + * bytes. The result is also guaranteed to be NUL terminated. Fail if + * there is not enough room in |buf| for the resulting string plus + * terminating NUL byte. + * + * Returns true if the operation succeeds, false otherwise. + */ +bool avb_str_concat(char* buf, + size_t buf_size, + const char* str1, + size_t str1_len, + const char* str2, + size_t str2_len); + +/* Like avb_malloc_() but prints a error using avb_error() if memory + * allocation fails. + */ +void* avb_malloc(size_t size) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Like avb_malloc() but sets the memory with zeroes. */ +void* avb_calloc(size_t size) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Duplicates a NUL-terminated string. Returns NULL on OOM. */ +char* avb_strdup(const char* str) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Duplicates a NULL-terminated array of NUL-terminated strings by + * concatenating them. The returned string will be + * NUL-terminated. Returns NULL on OOM. + */ +char* avb_strdupv(const char* str, + ...) AVB_ATTR_WARN_UNUSED_RESULT AVB_ATTR_SENTINEL; + +/* Finds the first occurrence of |needle| in the string |haystack| + * where both strings are NUL-terminated strings. The terminating NUL + * bytes are not compared. + * + * Returns NULL if not found, otherwise points into |haystack| for the + * first occurrence of |needle|. + */ +const char* avb_strstr(const char* haystack, + const char* needle) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Finds the first occurrence of |str| in the NULL-terminated string + * array |strings|. Each element in |strings| must be + * NUL-terminated. The string given by |str| need not be + * NUL-terminated but its size must be given in |str_size|. + * + * Returns NULL if not found, otherwise points into |strings| for the + * first occurrence of |str|. + */ +const char* avb_strv_find_str(const char* const* strings, + const char* str, + size_t str_size); + +/* Replaces all occurrences of |search| with |replace| in |str|. + * + * Returns a newly allocated string or NULL if out of memory. + */ +char* avb_replace(const char* str, + const char* search, + const char* replace) AVB_ATTR_WARN_UNUSED_RESULT; + +/* Calculates the CRC-32 for data in |buf| of size |buf_size|. */ +uint32_t avb_crc32(const uint8_t* buf, size_t buf_size); + +/* Returns the basename of |str|. This is defined as the last path + * component, assuming the normal POSIX separator '/'. If there are no + * separators, returns |str|. + */ +const char* avb_basename(const char* str); + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_UTIL_H_ */ diff --git a/libavb/avb_vbmeta_image.c b/libavb/avb_vbmeta_image.c new file mode 100644 index 0000000..21bbf92 --- a/dev/null +++ b/libavb/avb_vbmeta_image.c @@ -0,0 +1,308 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_vbmeta_image.h" +#include "avb_crypto.h" +#include "avb_rsa.h" +#include "avb_sha.h" +#include "avb_util.h" +#include "avb_version.h" + +AvbVBMetaVerifyResult avb_vbmeta_image_verify( + const uint8_t* data, + size_t length, + const uint8_t** out_public_key_data, + size_t* out_public_key_length) { + AvbVBMetaVerifyResult ret; + AvbVBMetaImageHeader h; + uint8_t* computed_hash; + const AvbAlgorithmData* algorithm; + AvbSHA256Ctx sha256_ctx; + AvbSHA512Ctx sha512_ctx; + const uint8_t* header_block; + const uint8_t* authentication_block; + const uint8_t* auxiliary_block; + int verification_result; + + ret = AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER; + + if (out_public_key_data != NULL) { + *out_public_key_data = NULL; + } + if (out_public_key_length != NULL) { + *out_public_key_length = 0; + } + + /* Ensure magic is correct. */ + if (avb_safe_memcmp(data, AVB_MAGIC, AVB_MAGIC_LEN) != 0) { + avb_error("Magic is incorrect.\n"); + goto out; + } + + /* Before we byteswap, ensure length is long enough. */ + if (length < sizeof(AvbVBMetaImageHeader)) { + avb_error("Length is smaller than header.\n"); + goto out; + } + avb_vbmeta_image_header_to_host_byte_order((const AvbVBMetaImageHeader*)data, + &h); + + /* Ensure we don't attempt to access any fields if we do not meet + * the specified minimum version of libavb. + */ + if ((h.required_libavb_version_major != AVB_VERSION_MAJOR) || + (h.required_libavb_version_minor > AVB_VERSION_MINOR)) { + avb_error("Mismatch between image version and libavb version.\n"); + ret = AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION; + goto out; + } + + /* Ensure |release_string| ends with a NUL byte. */ + if (h.release_string[AVB_RELEASE_STRING_SIZE - 1] != '\0') { + avb_error("Release string does not end with a NUL byte.\n"); + goto out; + } + + /* Ensure inner block sizes are multiple of 64. */ + if ((h.authentication_data_block_size & 0x3f) != 0 || + (h.auxiliary_data_block_size & 0x3f) != 0) { + avb_error("Block size is not a multiple of 64.\n"); + goto out; + } + + /* Ensure block sizes all add up to at most |length|. */ + uint64_t block_total = sizeof(AvbVBMetaImageHeader); + if (!avb_safe_add_to(&block_total, h.authentication_data_block_size) || + !avb_safe_add_to(&block_total, h.auxiliary_data_block_size)) { + avb_error("Overflow while computing size of boot image.\n"); + goto out; + } + if (block_total > length) { + avb_error("Block sizes add up to more than given length.\n"); + goto out; + } + + uintptr_t data_ptr = (uintptr_t)data; + /* Ensure passed in memory doesn't wrap. */ + if (!avb_safe_add(NULL, (uint64_t)data_ptr, length)) { + avb_error("Boot image location and length mismatch.\n"); + goto out; + } + + /* Ensure hash and signature are entirely in the Authentication data block. */ + uint64_t hash_end; + if (!avb_safe_add(&hash_end, h.hash_offset, h.hash_size) || + hash_end > h.authentication_data_block_size) { + avb_error("Hash is not entirely in its block.\n"); + goto out; + } + uint64_t signature_end; + if (!avb_safe_add(&signature_end, h.signature_offset, h.signature_size) || + signature_end > h.authentication_data_block_size) { + avb_error("Signature is not entirely in its block.\n"); + goto out; + } + + /* Ensure public key is entirely in the Auxiliary data block. */ + uint64_t pubkey_end; + if (!avb_safe_add(&pubkey_end, h.public_key_offset, h.public_key_size) || + pubkey_end > h.auxiliary_data_block_size) { + avb_error("Public key is not entirely in its block.\n"); + goto out; + } + + /* Ensure public key metadata (if set) is entirely in the Auxiliary + * data block. */ + if (h.public_key_metadata_size > 0) { + uint64_t pubkey_md_end; + if (!avb_safe_add(&pubkey_md_end, + h.public_key_metadata_offset, + h.public_key_metadata_size) || + pubkey_md_end > h.auxiliary_data_block_size) { + avb_error("Public key metadata is not entirely in its block.\n"); + goto out; + } + } + + /* Bail early if there's no hash or signature. */ + if (h.algorithm_type == AVB_ALGORITHM_TYPE_NONE) { + ret = AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED; + goto out; + } + + /* Ensure algorithm field is supported. */ + algorithm = avb_get_algorithm_data(h.algorithm_type); + if (!algorithm) { + avb_error("Invalid or unknown algorithm.\n"); + goto out; + } + + /* Bail if the embedded hash size doesn't match the chosen algorithm. */ + if (h.hash_size != algorithm->hash_len) { + avb_error("Embedded hash has wrong size.\n"); + goto out; + } + + /* No overflow checks needed from here-on after since all block + * sizes and offsets have been verified above. + */ + + header_block = data; + authentication_block = header_block + sizeof(AvbVBMetaImageHeader); + auxiliary_block = authentication_block + h.authentication_data_block_size; + + switch (h.algorithm_type) { + /* Explicit fall-through: */ + case AVB_ALGORITHM_TYPE_SHA256_RSA2048: + case AVB_ALGORITHM_TYPE_SHA256_RSA4096: + case AVB_ALGORITHM_TYPE_SHA256_RSA8192: + avb_sha256_init(&sha256_ctx); + avb_sha256_update( + &sha256_ctx, header_block, sizeof(AvbVBMetaImageHeader)); + avb_sha256_update( + &sha256_ctx, auxiliary_block, h.auxiliary_data_block_size); + computed_hash = avb_sha256_final(&sha256_ctx); + break; + /* Explicit fall-through: */ + case AVB_ALGORITHM_TYPE_SHA512_RSA2048: + case AVB_ALGORITHM_TYPE_SHA512_RSA4096: + case AVB_ALGORITHM_TYPE_SHA512_RSA8192: + avb_sha512_init(&sha512_ctx); + avb_sha512_update( + &sha512_ctx, header_block, sizeof(AvbVBMetaImageHeader)); + avb_sha512_update( + &sha512_ctx, auxiliary_block, h.auxiliary_data_block_size); + computed_hash = avb_sha512_final(&sha512_ctx); + break; + default: + avb_error("Unknown algorithm.\n"); + goto out; + } + + if (avb_safe_memcmp(authentication_block + h.hash_offset, + computed_hash, + h.hash_size) != 0) { + avb_error("Hash does not match!\n"); + ret = AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH; + goto out; + } + + verification_result = + avb_rsa_verify(auxiliary_block + h.public_key_offset, + h.public_key_size, + authentication_block + h.signature_offset, + h.signature_size, + authentication_block + h.hash_offset, + h.hash_size, + algorithm->padding, + algorithm->padding_len); + + if (verification_result == 0) { + ret = AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH; + goto out; + } + + if (h.public_key_size > 0) { + if (out_public_key_data != NULL) { + *out_public_key_data = auxiliary_block + h.public_key_offset; + } + if (out_public_key_length != NULL) { + *out_public_key_length = h.public_key_size; + } + } + + ret = AVB_VBMETA_VERIFY_RESULT_OK; + +out: + return ret; +} + +void avb_vbmeta_image_header_to_host_byte_order(const AvbVBMetaImageHeader* src, + AvbVBMetaImageHeader* dest) { + avb_memcpy(dest, src, sizeof(AvbVBMetaImageHeader)); + + dest->required_libavb_version_major = + avb_be32toh(dest->required_libavb_version_major); + dest->required_libavb_version_minor = + avb_be32toh(dest->required_libavb_version_minor); + + dest->authentication_data_block_size = + avb_be64toh(dest->authentication_data_block_size); + dest->auxiliary_data_block_size = + avb_be64toh(dest->auxiliary_data_block_size); + + dest->algorithm_type = avb_be32toh(dest->algorithm_type); + + dest->hash_offset = avb_be64toh(dest->hash_offset); + dest->hash_size = avb_be64toh(dest->hash_size); + + dest->signature_offset = avb_be64toh(dest->signature_offset); + dest->signature_size = avb_be64toh(dest->signature_size); + + dest->public_key_offset = avb_be64toh(dest->public_key_offset); + dest->public_key_size = avb_be64toh(dest->public_key_size); + + dest->public_key_metadata_offset = + avb_be64toh(dest->public_key_metadata_offset); + dest->public_key_metadata_size = avb_be64toh(dest->public_key_metadata_size); + + dest->descriptors_offset = avb_be64toh(dest->descriptors_offset); + dest->descriptors_size = avb_be64toh(dest->descriptors_size); + + dest->rollback_index = avb_be64toh(dest->rollback_index); + dest->flags = avb_be32toh(dest->flags); +} + +const char* avb_vbmeta_verify_result_to_string(AvbVBMetaVerifyResult result) { + const char* ret = NULL; + + switch (result) { + case AVB_VBMETA_VERIFY_RESULT_OK: + ret = "OK"; + break; + case AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED: + ret = "OK_NOT_SIGNED"; + break; + case AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER: + ret = "INVALID_VBMETA_HEADER"; + break; + case AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION: + ret = "UNSUPPORTED_VERSION"; + break; + case AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH: + ret = "HASH_MISMATCH"; + break; + case AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH: + ret = "SIGNATURE_MISMATCH"; + break; + /* Do not add a 'default:' case here because of -Wswitch. */ + } + + if (ret == NULL) { + avb_error("Unknown AvbVBMetaVerifyResult value.\n"); + ret = "(unknown)"; + } + + return ret; +} diff --git a/libavb/avb_vbmeta_image.h b/libavb/avb_vbmeta_image.h new file mode 100644 index 0000000..90c3a54 --- a/dev/null +++ b/libavb/avb_vbmeta_image.h @@ -0,0 +1,290 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_VBMETA_IMAGE_H_ +#define AVB_VBMETA_IMAGE_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +#include "avb_crypto.h" +#include "avb_descriptor.h" + +/* Size of the vbmeta image header. */ +#define AVB_VBMETA_IMAGE_HEADER_SIZE 256 + +/* Magic for the vbmeta image header. */ +#define AVB_MAGIC "AVB0" +#define AVB_MAGIC_LEN 4 + +/* Maximum size of the release string including the terminating NUL byte. */ +#define AVB_RELEASE_STRING_SIZE 48 + +/* Flags for the vbmeta image. + * + * AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED: If this flag is set, + * hashtree image verification will be disabled. + */ +typedef enum { + AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED = (1 << 0) +} AvbVBMetaImageFlags; + +/* Binary format for header of the vbmeta image. + * + * The vbmeta image consists of three blocks: + * + * +-----------------------------------------+ + * | Header data - fixed size | + * +-----------------------------------------+ + * | Authentication data - variable size | + * +-----------------------------------------+ + * | Auxiliary data - variable size | + * +-----------------------------------------+ + * + * The "Header data" block is described by this struct and is always + * |AVB_VBMETA_IMAGE_HEADER_SIZE| bytes long. + * + * The "Authentication data" block is |authentication_data_block_size| + * bytes long and contains the hash and signature used to authenticate + * the vbmeta image. The type of the hash and signature is defined by + * the |algorithm_type| field. + * + * The "Auxiliary data" is |auxiliary_data_block_size| bytes long and + * contains the auxiliary data including the public key used to make + * the signature and descriptors. + * + * The public key is at offset |public_key_offset| with size + * |public_key_size| in this block. The size of the public key data is + * defined by the |algorithm_type| field. The format of the public key + * data is described in the |AvbRSAPublicKeyHeader| struct. + * + * The descriptors starts at |descriptors_offset| from the beginning + * of the "Auxiliary Data" block and take up |descriptors_size| + * bytes. Each descriptor is stored as a |AvbDescriptor| with tag and + * number of bytes following. The number of descriptors can be + * determined by walking this data until |descriptors_size| is + * exhausted. + * + * The size of each of the "Authentication data" and "Auxiliary data" + * blocks must be divisible by 64. This is to ensure proper alignment. + * + * Descriptors are free-form blocks stored in a part of the vbmeta + * image subject to the same integrity checks as the rest of the + * image. See the documentation for |AvbDescriptor| for well-known + * descriptors. See avb_descriptor_foreach() for a convenience + * function to iterate over descriptors. + * + * This struct is versioned, see the |required_libavb_version_major| + * and |required_libavb_version_minor| fields. This represents the + * minimum version of libavb required to verify the header and depends + * on the features (e.g. algorithms, descriptors) used. Note that this + * may be 1.0 even if generated by an avbtool from 1.4 but where no + * features introduced after 1.0 has been used. See the "Versioning + * and compatibility" section in the README.md file for more details. + * + * All fields are stored in network byte order when serialized. To + * generate a copy with fields swapped to native byte order, use the + * function avb_vbmeta_image_header_to_host_byte_order(). + * + * Before reading and/or using any of this data, you MUST verify it + * using avb_vbmeta_image_verify() and reject it unless it's signed by + * a known good public key. + */ +typedef struct AvbVBMetaImageHeader { + /* 0: Four bytes equal to "AVB0" (AVB_MAGIC). */ + uint8_t magic[AVB_MAGIC_LEN]; + + /* 4: The major version of libavb required for this header. */ + uint32_t required_libavb_version_major; + /* 8: The minor version of libavb required for this header. */ + uint32_t required_libavb_version_minor; + + /* 12: The size of the signature block. */ + uint64_t authentication_data_block_size; + /* 20: The size of the auxiliary data block. */ + uint64_t auxiliary_data_block_size; + + /* 28: The verification algorithm used, see |AvbAlgorithmType| enum. */ + uint32_t algorithm_type; + + /* 32: Offset into the "Authentication data" block of hash data. */ + uint64_t hash_offset; + /* 40: Length of the hash data. */ + uint64_t hash_size; + + /* 48: Offset into the "Authentication data" block of signature data. */ + uint64_t signature_offset; + /* 56: Length of the signature data. */ + uint64_t signature_size; + + /* 64: Offset into the "Auxiliary data" block of public key data. */ + uint64_t public_key_offset; + /* 72: Length of the public key data. */ + uint64_t public_key_size; + + /* 80: Offset into the "Auxiliary data" block of public key metadata. */ + uint64_t public_key_metadata_offset; + /* 88: Length of the public key metadata. Must be set to zero if there + * is no public key metadata. + */ + uint64_t public_key_metadata_size; + + /* 96: Offset into the "Auxiliary data" block of descriptor data. */ + uint64_t descriptors_offset; + /* 104: Length of descriptor data. */ + uint64_t descriptors_size; + + /* 112: The rollback index which can be used to prevent rollback to + * older versions. + */ + uint64_t rollback_index; + + /* 120: Flags from the AvbVBMetaImageFlags enumeration. This must be + * set to zero if the vbmeta image is not a top-level image. + */ + uint32_t flags; + + /* 124: Reserved to ensure |release_string| start on a 16-byte + * boundary. Must be set to zeroes. + */ + uint8_t reserved0[4]; + + /* 128: The release string from avbtool, e.g. "avbtool 1.0.0" or + * "avbtool 1.0.0 xyz_board Git-234abde89". Is guaranteed to be NUL + * terminated. Applications must not make assumptions about how this + * string is formatted. + */ + uint8_t release_string[AVB_RELEASE_STRING_SIZE]; + + /* 176: Padding to ensure struct is size AVB_VBMETA_IMAGE_HEADER_SIZE + * bytes. This must be set to zeroes. + */ + uint8_t reserved[80]; +} AVB_ATTR_PACKED AvbVBMetaImageHeader; + +/* Copies |src| to |dest|, byte-swapping fields in the process. + * + * Make sure you've verified |src| using avb_vbmeta_image_verify() + * before accessing the data and/or using this function. + */ +void avb_vbmeta_image_header_to_host_byte_order(const AvbVBMetaImageHeader* src, + AvbVBMetaImageHeader* dest); + +/* Return codes used in avb_vbmeta_image_verify(). + * + * AVB_VBMETA_VERIFY_RESULT_OK is returned if the vbmeta image header + * is valid, the hash is correct and the signature is correct. Keep in + * mind that you still need to check that you know the public key used + * to sign the image, see avb_vbmeta_image_verify() for details. + * + * AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED is returned if the vbmeta + * image header is valid but there is no signature or hash. + * + * AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER is returned if the + * header of the vbmeta image is invalid, for example, invalid magic + * or inconsistent data. + * + * AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION is returned if a) the + * vbmeta image requires a minimum version of libavb which exceeds the + * version of libavb used; or b) the vbmeta image major version + * differs from the major version of libavb in use. + * + * AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH is returned if the hash + * stored in the "Authentication data" block does not match the + * calculated hash. + * + * AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH is returned if the + * signature stored in the "Authentication data" block is invalid or + * doesn't match the public key stored in the vbmeta image. + */ +typedef enum { + AVB_VBMETA_VERIFY_RESULT_OK, + AVB_VBMETA_VERIFY_RESULT_OK_NOT_SIGNED, + AVB_VBMETA_VERIFY_RESULT_INVALID_VBMETA_HEADER, + AVB_VBMETA_VERIFY_RESULT_UNSUPPORTED_VERSION, + AVB_VBMETA_VERIFY_RESULT_HASH_MISMATCH, + AVB_VBMETA_VERIFY_RESULT_SIGNATURE_MISMATCH, +} AvbVBMetaVerifyResult; + +/* Get a textual representation of |result|. */ +const char* avb_vbmeta_verify_result_to_string(AvbVBMetaVerifyResult result); + +/* Checks that vbmeta image at |data| of size |length| is a valid + * vbmeta image. The complete contents of the vbmeta image must be + * passed in. It's fine if |length| is bigger than the actual image, + * typically callers of this function will load the entire contents of + * the 'vbmeta_a' or 'vbmeta_b' partition and pass in its length (for + * example, 1 MiB). + * + * See the |AvbVBMetaImageHeader| struct for information about the + * three blocks (header, authentication, auxiliary) that make up a + * vbmeta image. + * + * If the function returns |AVB_VBMETA_VERIFY_RESULT_OK| and + * |out_public_key_data| is non-NULL, it will be set to point inside + * |data| for where the serialized public key data is stored and + * |out_public_key_length|, if non-NULL, will be set to the length of + * the public key data. If there is no public key in the metadata then + * |out_public_key_data| is set to NULL. + * + * See the |AvbVBMetaVerifyResult| enum for possible return values. + * + * VERY IMPORTANT: + * + * 1. Even if |AVB_VBMETA_VERIFY_RESULT_OK| is returned, you still + * need to check that the public key embedded in the image + * matches a known key! You can use 'avbtool extract_public_key' + * to extract the key (at build time, then store it along your + * code) and compare it to what is returned in + * |out_public_key_data|. + * + * 2. You need to check the |rollback_index| field against a stored + * value in NVRAM and reject the vbmeta image if the value in + * NVRAM is bigger than |rollback_index|. You must also update + * the value stored in NVRAM to the smallest value of + * |rollback_index| field from boot images in all bootable and + * authentic slots marked as GOOD. + * + * This is a low-level function to only verify the vbmeta data - you + * are likely looking for avb_slot_verify() instead for verifying + * integrity data for a whole set of partitions. + */ +AvbVBMetaVerifyResult avb_vbmeta_image_verify( + const uint8_t* data, + size_t length, + const uint8_t** out_public_key_data, + size_t* out_public_key_length) AVB_ATTR_WARN_UNUSED_RESULT; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_VBMETA_IMAGE_H_ */ diff --git a/libavb/avb_version.c b/libavb/avb_version.c new file mode 100644 index 0000000..31f5fa6 --- a/dev/null +++ b/libavb/avb_version.c @@ -0,0 +1,34 @@ +/* + * Copyright (C) 2017 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_version.h" + +#define AVB_QUOTE(str) #str +#define AVB_EXPAND_AND_QUOTE(str) AVB_QUOTE(str) + +/* Keep in sync with get_release_string() in avbtool. */ +const char* avb_version_string(void) { + return AVB_EXPAND_AND_QUOTE(AVB_VERSION_MAJOR) "." AVB_EXPAND_AND_QUOTE( + AVB_VERSION_MINOR) "." AVB_EXPAND_AND_QUOTE(AVB_VERSION_SUB); +} diff --git a/libavb/avb_version.h b/libavb/avb_version.h new file mode 100644 index 0000000..7757d09 --- a/dev/null +++ b/libavb/avb_version.h @@ -0,0 +1,63 @@ +/* + * Copyright (C) 2017 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION) +#error "Never include this file directly, include libavb.h instead." +#endif + +#ifndef AVB_VERSION_H_ +#define AVB_VERSION_H_ + +#include "avb_sysdeps.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* The version number of AVB - keep in sync with avbtool. */ +#define AVB_VERSION_MAJOR 1 +#define AVB_VERSION_MINOR 0 +#define AVB_VERSION_SUB 0 + +/* Returns a NUL-terminated string for the libavb version in use. The + * returned string usually looks like "%d.%d.%d". Applications must + * not make assumptions about the content of this string. + * + * Boot loaders should display this string in debug/diagnostics output + * to aid with debugging. + * + * This is similar to the string put in the |release_string| string + * field in the VBMeta struct by avbtool. + */ +const char* avb_version_string(void); + +/* TODO: remove when there are no more users of AVB_{MAJOR,MINOR}_VERSION. */ +#define AVB_MAJOR_VERSION AVB_VERSION_MAJOR +#define AVB_MINOR_VERSION AVB_VERSION_MINOR + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_VERSION_H_ */ diff --git a/libavb/libavb.h b/libavb/libavb.h new file mode 100644 index 0000000..d511584 --- a/dev/null +++ b/libavb/libavb.h @@ -0,0 +1,50 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef LIBAVB_H_ +#define LIBAVB_H_ + +/* The AVB_INSIDE_LIBAVB_H preprocessor symbol is used to enforce + * library users to include only this file. All public interfaces, and + * only public interfaces, must be included here. + */ + +#define AVB_INSIDE_LIBAVB_H +#include "avb_chain_partition_descriptor.h" +#include "avb_crypto.h" +#include "avb_descriptor.h" +#include "avb_footer.h" +#include "avb_hash_descriptor.h" +#include "avb_hashtree_descriptor.h" +#include "avb_kernel_cmdline_descriptor.h" +#include "avb_ops.h" +#include "avb_property_descriptor.h" +#include "avb_slot_verify.h" +#include "avb_sysdeps.h" +#include "avb_util.h" +#include "avb_vbmeta_image.h" +#include "avb_version.h" +#undef AVB_INSIDE_LIBAVB_H + +#endif /* LIBAVB_H_ */ diff --git a/libavb_ab/avb_ab_flow.c b/libavb_ab/avb_ab_flow.c new file mode 100644 index 0000000..4750c23 --- a/dev/null +++ b/libavb_ab/avb_ab_flow.c @@ -0,0 +1,536 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#define LOG_TAG "control_avb" + +#include <log/log.h> +#include "avb_ab_flow.h" +#include <stdio.h> + +bool avb_ab_data_verify_and_byteswap(const AvbABData* src, AvbABData* dest) { + /* Ensure magic is correct. */ + if (avb_safe_memcmp(src->magic, AVB_AB_MAGIC, AVB_AB_MAGIC_LEN) != 0) { + ALOGE("Magic is incorrect.\n"); + return false; + } + + avb_memcpy(dest, src, sizeof(AvbABData)); + dest->crc32 = avb_be32toh(dest->crc32); + + /* Ensure we don't attempt to access any fields if the major version + * is not supported. + */ + if (dest->version_major > AVB_AB_MAJOR_VERSION) { + ALOGE("No support for given major version.\n"); + return false; + } + + /* Bail if CRC32 doesn't match. */ + if (dest->crc32 != + avb_crc32((const uint8_t*)dest, sizeof(AvbABData) - sizeof(uint32_t))) { + ALOGE("CRC32 does not match.\n"); + return false; + } + + return true; +} + +void avb_ab_data_update_crc_and_byteswap(const AvbABData* src, + AvbABData* dest) { + avb_memcpy(dest, src, sizeof(AvbABData)); + dest->crc32 = avb_htobe32( + avb_crc32((const uint8_t*)dest, sizeof(AvbABData) - sizeof(uint32_t))); +} + +void avb_ab_data_init(AvbABData* data) { + avb_memset(data, '\0', sizeof(AvbABData)); + avb_memcpy(data->magic, AVB_AB_MAGIC, AVB_AB_MAGIC_LEN); + data->version_major = AVB_AB_MAJOR_VERSION; + data->version_minor = AVB_AB_MINOR_VERSION; + data->slots[0].priority = AVB_AB_MAX_PRIORITY; + data->slots[0].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + data->slots[0].successful_boot = 0; + data->slots[1].priority = AVB_AB_MAX_PRIORITY - 1; + data->slots[1].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + data->slots[1].successful_boot = 0; +} + +/* The AvbABData struct is stored 2048 bytes into the 'misc' partition + * following the 'struct bootloader_message' field. The struct is + * compatible with the guidelines in bootable/recovery/bootloader.h - + * e.g. it is stored in the |slot_suffix| field, starts with a + * NUL-byte, and is 32 bytes long. + */ +#define AB_METADATA_MISC_PARTITION_OFFSET 2048 + +AvbIOResult avb_ab_data_read(AvbABOps* ab_ops, AvbABData* data) { + AvbOps* ops = ab_ops->ops; + AvbABData serialized; + AvbIOResult io_ret; + size_t num_bytes_read; + + io_ret = ops->read_from_partition(ops, + "misc", + AB_METADATA_MISC_PARTITION_OFFSET, + sizeof(AvbABData), + &serialized, + &num_bytes_read); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + return AVB_IO_RESULT_ERROR_OOM; + } else if (io_ret != AVB_IO_RESULT_OK || + num_bytes_read != sizeof(AvbABData)) { + ALOGE("Error reading A/B metadata.\n"); + return AVB_IO_RESULT_ERROR_IO; + } + + if (!avb_ab_data_verify_and_byteswap(&serialized, data)) { + ALOGE( + "Error validating A/B metadata from disk. " + "Resetting and writing new A/B metadata to disk.\n"); + avb_ab_data_init(data); + return avb_ab_data_write(ab_ops, data); + } + + return AVB_IO_RESULT_OK; +} + +AvbIOResult avb_ab_data_write(AvbABOps* ab_ops, const AvbABData* data) { + AvbOps* ops = ab_ops->ops; + AvbABData serialized; + AvbIOResult io_ret; + + avb_ab_data_update_crc_and_byteswap(data, &serialized); + io_ret = ops->write_to_partition(ops, + "misc", + AB_METADATA_MISC_PARTITION_OFFSET, + sizeof(AvbABData), + &serialized); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + return AVB_IO_RESULT_ERROR_OOM; + } else if (io_ret != AVB_IO_RESULT_OK) { + ALOGE("*******Error writing A/B metadata.\n"); + return AVB_IO_RESULT_ERROR_IO; + } + return AVB_IO_RESULT_OK; +} + +static bool slot_is_bootable(AvbABSlotData* slot) { + return slot->priority > 0 && + (slot->successful_boot || (slot->tries_remaining > 0)); +} + +static void slot_set_unbootable(AvbABSlotData* slot) { + slot->priority = 0; + slot->tries_remaining = 0; + slot->successful_boot = 0; +} + +/* Ensure all unbootable and/or illegal states are marked as the + * canonical 'unbootable' state, e.g. priority=0, tries_remaining=0, + * and successful_boot=0. + */ +static void slot_normalize(AvbABSlotData* slot) { + if (slot->priority > 0) { + if (slot->tries_remaining == 0 && !slot->successful_boot) { + /* We've exhausted all tries -> unbootable. */ + slot_set_unbootable(slot); + } + if (slot->tries_remaining > 0 && slot->successful_boot) { + /* Illegal state - avb_ab_mark_slot_successful() will clear + * tries_remaining when setting successful_boot. + */ + slot_set_unbootable(slot); + } + } else { + slot_set_unbootable(slot); + } +} + +static const char* slot_suffixes[2] = {"_a", "_b"}; + +/* Helper function to load metadata - returns AVB_IO_RESULT_OK on + * success, error code otherwise. + */ +static AvbIOResult load_metadata(AvbABOps* ab_ops, + AvbABData* ab_data, + AvbABData* ab_data_orig) { + AvbIOResult io_ret; + + io_ret = ab_ops->read_ab_metadata(ab_ops, ab_data); + if (io_ret != AVB_IO_RESULT_OK) { + ALOGE("I/O error while loading A/B metadata.\n"); + return io_ret; + } + *ab_data_orig = *ab_data; + + /* Ensure data is normalized, e.g. illegal states will be marked as + * unbootable and all unbootable states are represented with + * (priority=0, tries_remaining=0, successful_boot=0). + */ + slot_normalize(&ab_data->slots[0]); + slot_normalize(&ab_data->slots[1]); + return AVB_IO_RESULT_OK; +} + +/* Writes A/B metadata to disk only if it has changed - returns + * AVB_IO_RESULT_OK on success, error code otherwise. + */ +static AvbIOResult save_metadata_if_changed(AvbABOps* ab_ops, + AvbABData* ab_data, + AvbABData* ab_data_orig) { + if (avb_safe_memcmp(ab_data, ab_data_orig, sizeof(AvbABData)) != 0) { + ALOGE("Writing A/B metadata to disk.\n"); + return ab_ops->write_ab_metadata(ab_ops, ab_data); + } + return AVB_IO_RESULT_OK; +} + +AvbABFlowResult avb_ab_flow(AvbABOps* ab_ops, + const char* const* requested_partitions, + bool allow_verification_error, + AvbSlotVerifyData** out_data) { + AvbOps* ops = ab_ops->ops; + AvbSlotVerifyData* slot_data[2] = {NULL, NULL}; + AvbSlotVerifyData* data = NULL; + AvbABFlowResult ret; + AvbABData ab_data, ab_data_orig; + size_t slot_index_to_boot, n; + AvbIOResult io_ret; + bool saw_and_allowed_verification_error = false; + + io_ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + + /* Validate all bootable slots. */ + for (n = 0; n < 2; n++) { + if (slot_is_bootable(&ab_data.slots[n])) { + AvbSlotVerifyResult verify_result; + bool set_slot_unbootable = false; + + verify_result = avb_slot_verify(ops, + requested_partitions, + slot_suffixes[n], + allow_verification_error, + &slot_data[n]); + switch (verify_result) { + case AVB_SLOT_VERIFY_RESULT_ERROR_OOM: + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + + case AVB_SLOT_VERIFY_RESULT_ERROR_IO: + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + + case AVB_SLOT_VERIFY_RESULT_OK: + break; + + case AVB_SLOT_VERIFY_RESULT_ERROR_INVALID_METADATA: + case AVB_SLOT_VERIFY_RESULT_ERROR_UNSUPPORTED_VERSION: + /* Even with |allow_verification_error| these mean game over. */ + set_slot_unbootable = true; + break; + + /* explicit fallthrough. */ + case AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION: + case AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX: + case AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED: + if (allow_verification_error) { + /* Do nothing since we allow this. */ + avb_debugv("Allowing slot ", + slot_suffixes[n], + " which verified " + "with result ", + avb_slot_verify_result_to_string(verify_result), + " because |allow_verification_error| is true.\n", + NULL); + saw_and_allowed_verification_error = true; + } else { + set_slot_unbootable = true; + } + break; + } + + if (set_slot_unbootable) { + ALOGE("Error verifying slot %s with result %s - setting unbootable.", + slot_suffixes[n], avb_slot_verify_result_to_string(verify_result)); + slot_set_unbootable(&ab_data.slots[n]); + } + } + } + + if (slot_is_bootable(&ab_data.slots[0]) && + slot_is_bootable(&ab_data.slots[1])) { + if (ab_data.slots[1].priority > ab_data.slots[0].priority) { + slot_index_to_boot = 1; + } else { + slot_index_to_boot = 0; + } + } else if (slot_is_bootable(&ab_data.slots[0])) { + slot_index_to_boot = 0; + } else if (slot_is_bootable(&ab_data.slots[1])) { + slot_index_to_boot = 1; + } else { + /* No bootable slots! */ + ALOGE("No bootable slots found.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS; + goto out; + } + + /* Update stored rollback index such that the stored rollback index + * is the largest value supporting all currently bootable slots. Do + * this for every rollback index location. + */ + for (n = 0; n < AVB_MAX_NUMBER_OF_ROLLBACK_INDEX_LOCATIONS; n++) { + uint64_t rollback_index_value = 0; + + if (slot_data[0] != NULL && slot_data[1] != NULL) { + uint64_t a_rollback_index = slot_data[0]->rollback_indexes[n]; + uint64_t b_rollback_index = slot_data[1]->rollback_indexes[n]; + rollback_index_value = + (a_rollback_index < b_rollback_index ? a_rollback_index + : b_rollback_index); + } else if (slot_data[0] != NULL) { + rollback_index_value = slot_data[0]->rollback_indexes[n]; + } else if (slot_data[1] != NULL) { + rollback_index_value = slot_data[1]->rollback_indexes[n]; + } + + if (rollback_index_value != 0) { + uint64_t current_rollback_index_value; + io_ret = ops->read_rollback_index(ops, n, ¤t_rollback_index_value); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + ALOGE("Error getting rollback index for slot.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + if (current_rollback_index_value != rollback_index_value) { + io_ret = ops->write_rollback_index(ops, n, rollback_index_value); + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + goto out; + } else if (io_ret != AVB_IO_RESULT_OK) { + ALOGE("Error setting stored rollback index.\n"); + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + goto out; + } + } + } + } + + /* Finally, select this slot. */ + avb_assert(slot_data[slot_index_to_boot] != NULL); + data = slot_data[slot_index_to_boot]; + slot_data[slot_index_to_boot] = NULL; + if (saw_and_allowed_verification_error) { + avb_assert(allow_verification_error); + ret = AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR; + } else { + ret = AVB_AB_FLOW_RESULT_OK; + } + + /* ... and decrement tries remaining, if applicable. */ + if (!ab_data.slots[slot_index_to_boot].successful_boot && + ab_data.slots[slot_index_to_boot].tries_remaining > 0) { + ab_data.slots[slot_index_to_boot].tries_remaining -= 1; + } + +out: + io_ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + if (io_ret != AVB_IO_RESULT_OK) { + if (io_ret == AVB_IO_RESULT_ERROR_OOM) { + ret = AVB_AB_FLOW_RESULT_ERROR_OOM; + } else { + ret = AVB_AB_FLOW_RESULT_ERROR_IO; + } + if (data != NULL) { + avb_slot_verify_data_free(data); + data = NULL; + } + } + + for (n = 0; n < 2; n++) { + if (slot_data[n] != NULL) { + avb_slot_verify_data_free(slot_data[n]); + } + } + + if (out_data != NULL) { + *out_data = data; + } else { + if (data != NULL) { + avb_slot_verify_data_free(data); + } + } + + return ret; +} + +AvbIOResult avb_ab_mark_slot_active(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + unsigned int other_slot_number; + AvbIOResult ret; + + ALOGE("*************come to avb_ab_mark_slot_active slot:%d", slot_number); + + if (slot_number >= 2) { + return AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION; + } + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + ALOGE("ab_data.slots[0].priority: %d\n", ab_data.slots[0].priority); + ALOGE("ab_data.slots[0].tries_remaining: %d\n", ab_data.slots[0].tries_remaining); + ALOGE("ab_data.slots[0].successful_boot: %d\n", ab_data.slots[0].successful_boot); + ALOGE("ab_data.slots[1].priority: %d\n", ab_data.slots[1].priority); + ALOGE("ab_data.slots[1].tries_remaining: %d\n", ab_data.slots[1].tries_remaining); + ALOGE("ab_data.slots[1].successful_boot: %d\n", ab_data.slots[1].successful_boot); + + /* Make requested slot top priority, unsuccessful, and with max tries. */ + ab_data.slots[slot_number].priority = AVB_AB_MAX_PRIORITY; + ab_data.slots[slot_number].tries_remaining = AVB_AB_MAX_TRIES_REMAINING; + ab_data.slots[slot_number].successful_boot = 0; + + /* Ensure other slot doesn't have as high a priority. */ + other_slot_number = 1 - slot_number; + + ALOGE("come to avb_ab_mark_slot_active other_slot_number: %d\n", other_slot_number); + ALOGE("ab_data.slots[other_slot_number].priority: %d\n", ab_data.slots[other_slot_number].priority); + + if (ab_data.slots[other_slot_number].priority == AVB_AB_MAX_PRIORITY) { + ab_data.slots[other_slot_number].priority = AVB_AB_MAX_PRIORITY - 1; + } + + ALOGE("ab_data.slots[other_slot_number].priority: %d\n", ab_data.slots[other_slot_number].priority); + + ret = AVB_IO_RESULT_OK; +out: + if (ret == AVB_IO_RESULT_OK) { + ALOGE("come to avb_ab_mark_slot_active 5\n"); + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +AvbIOResult avb_ab_mark_slot_unbootable(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + AvbIOResult ret; + + if (slot_number >= 2) { + return AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION; + } + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + slot_set_unbootable(&ab_data.slots[slot_number]); + + ret = AVB_IO_RESULT_OK; + +out: + if (ret == AVB_IO_RESULT_OK) { + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +AvbIOResult avb_ab_mark_slot_successful(AvbABOps* ab_ops, + unsigned int slot_number) { + AvbABData ab_data, ab_data_orig; + AvbIOResult ret; + + if (slot_number >= 2) { + return AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION; + } + + ret = load_metadata(ab_ops, &ab_data, &ab_data_orig); + if (ret != AVB_IO_RESULT_OK) { + goto out; + } + + if (!slot_is_bootable(&ab_data.slots[slot_number])) { + ALOGE("Cannot mark unbootable slot as successful.\n"); + ret = AVB_IO_RESULT_OK; + goto out; + } + + ab_data.slots[slot_number].tries_remaining = 0; + ab_data.slots[slot_number].successful_boot = 1; + + ret = AVB_IO_RESULT_OK; + +out: + if (ret == AVB_IO_RESULT_OK) { + ret = save_metadata_if_changed(ab_ops, &ab_data, &ab_data_orig); + } + return ret; +} + +const char* avb_ab_flow_result_to_string(AvbABFlowResult result) { + const char* ret = NULL; + + switch (result) { + case AVB_AB_FLOW_RESULT_OK: + ret = "OK"; + break; + + case AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR: + ret = "OK_WITH_VERIFICATION_ERROR"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_OOM: + ret = "ERROR_OOM"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_IO: + ret = "ERROR_IO"; + break; + + case AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS: + ret = "ERROR_NO_BOOTABLE_SLOTS"; + break; + /* Do not add a 'default:' case here because of -Wswitch. */ + } + + if (ret == NULL) { + ALOGE("Unknown AvbABFlowResult value.\n"); + ret = "(unknown)"; + } + + return ret; +} diff --git a/libavb_ab/avb_ab_flow.h b/libavb_ab/avb_ab_flow.h new file mode 100644 index 0000000..b2584d8 --- a/dev/null +++ b/libavb_ab/avb_ab_flow.h @@ -0,0 +1,253 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_AB_H) && !defined(AVB_COMPILATION) +#error \ + "Never include this file directly, include libavb_ab/libavb_ab.h instead." +#endif + +#ifndef AVB_AB_FLOW_H_ +#define AVB_AB_FLOW_H_ + +#include "avb_ab_ops.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Magic for the A/B struct when serialized. */ +#define AVB_AB_MAGIC "\0AB0" +#define AVB_AB_MAGIC_LEN 4 + +/* Versioning for the on-disk A/B metadata - keep in sync with avbtool. */ +#define AVB_AB_MAJOR_VERSION 1 +#define AVB_AB_MINOR_VERSION 0 + +/* Size of AvbABData struct. */ +#define AVB_AB_DATA_SIZE 32 + +/* Maximum values for slot data */ +#define AVB_AB_MAX_PRIORITY 15 +#define AVB_AB_MAX_TRIES_REMAINING 7 + +/* Struct used for recording per-slot metadata. + * + * When serialized, data is stored in network byte-order. + */ +typedef struct AvbABSlotData { + /* Slot priority. Valid values range from 0 to AVB_AB_MAX_PRIORITY, + * both inclusive with 1 being the lowest and AVB_AB_MAX_PRIORITY + * being the highest. The special value 0 is used to indicate the + * slot is unbootable. + */ + uint8_t priority; + + /* Number of times left attempting to boot this slot ranging from 0 + * to AVB_AB_MAX_TRIES_REMAINING. + */ + uint8_t tries_remaining; + + /* Non-zero if this slot has booted successfully, 0 otherwise. */ + uint8_t successful_boot; + + /* Reserved for future use. */ + uint8_t reserved[1]; +} AVB_ATTR_PACKED AvbABSlotData; + +/* Struct used for recording A/B metadata. + * + * When serialized, data is stored in network byte-order. + */ +typedef struct AvbABData { + /* Magic number used for identification - see AVB_AB_MAGIC. */ + uint8_t magic[AVB_AB_MAGIC_LEN]; + + /* Version of on-disk struct - see AVB_AB_{MAJOR,MINOR}_VERSION. */ + uint8_t version_major; + uint8_t version_minor; + + /* Padding to ensure |slots| field start eight bytes in. */ + uint8_t reserved1[2]; + + /* Per-slot metadata. */ + AvbABSlotData slots[2]; + + /* Reserved for future use. */ + uint8_t reserved2[12]; + + /* CRC32 of all 28 bytes preceding this field. */ + uint32_t crc32; +} AVB_ATTR_PACKED AvbABData; + +/* Copies |src| to |dest|, byte-swapping fields in the + * process. Returns false if the data is invalid (e.g. wrong magic, + * wrong CRC32 etc.), true otherwise. + */ +bool avb_ab_data_verify_and_byteswap(const AvbABData* src, AvbABData* dest); + +/* Copies |src| to |dest|, byte-swapping fields in the process. Also + * updates the |crc32| field in |dest|. + */ +void avb_ab_data_update_crc_and_byteswap(const AvbABData* src, AvbABData* dest); + +/* Initializes |data| such that it has two slots and both slots have + * maximum tries remaining. The CRC is not set. + */ +void avb_ab_data_init(AvbABData* data); + +/* Reads A/B metadata from the 'misc' partition using |ops|. Returned + * data is properly byteswapped. Returns AVB_IO_RESULT_OK on + * success, error code otherwise. + * + * If the data read from disk is invalid (e.g. wrong magic or CRC + * checksum failure), the metadata will be reset using + * avb_ab_data_init() and then written to disk. + */ +AvbIOResult avb_ab_data_read(AvbABOps* ab_ops, AvbABData* data); + +/* Writes A/B metadata to the 'misc' partition using |ops|. This will + * byteswap and update the CRC as needed. Returns AVB_IO_RESULT_OK on + * success, error code otherwise. + */ +AvbIOResult avb_ab_data_write(AvbABOps* ab_ops, const AvbABData* data); + +/* Return codes used in avb_ab_flow(), see that function for + * documentation of each value. + */ +typedef enum { + AVB_AB_FLOW_RESULT_OK, + AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR, + AVB_AB_FLOW_RESULT_ERROR_OOM, + AVB_AB_FLOW_RESULT_ERROR_IO, + AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS +} AvbABFlowResult; + +/* Get a textual representation of |result|. */ +const char* avb_ab_flow_result_to_string(AvbABFlowResult result); + +/* High-level function to select a slot to boot. The following + * algorithm is used: + * + * 1. A/B metadata is loaded and validated using the + * read_ab_metadata() operation. Typically this means it's read from + * the 'misc' partition and if it's invalid then it's reset using + * avb_ab_data_init() and this reset metadata is returned. + * + * 2. All bootable slots listed in the A/B metadata are verified using + * avb_slot_verify(). If a slot is invalid or if it fails verification + * (and |allow_verification_error| is false, see below), it will be + * marked as unbootable in the A/B metadata and the metadata will be + * saved to disk before returning. + * + * 3. If there are no bootable slots, the value + * AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS is returned. + * + * 4. For each bootable slot, the Stored Rollback Indexes are updated + * such that for each rollback index location, the Stored Rollback + * Index is the largest number smaller than or equal to the Rollback + * Index of each slot. + * + * 5. The bootable slot with the highest priority is selected and + * returned in |out_data|. If this slot is already marked as + * successful, the A/B metadata is not modified. However, if the slot + * is not marked as bootable its |tries_remaining| count is + * decremented and the A/B metadata is saved to disk before returning. + * In either case the value AVB_AB_FLOW_RESULT_OK is returning. + * + * The partitions to load is given in |requested_partitions| as a + * NULL-terminated array of NUL-terminated strings. Typically the + * |requested_partitions| array only contains a single item for the + * boot partition, 'boot'. + * + * If the device is unlocked (and _only_ if it's unlocked), true + * should be passed in the |allow_verification_error| parameter. This + * will allow considering slots as verified even when + * avb_slot_verify() returns + * AVB_SLOT_VERIFY_RESULT_ERROR_PUBLIC_KEY_REJECTED, + * AVB_SLOT_VERIFY_RESULT_ERROR_VERIFICATION, or + * AVB_SLOT_VERIFY_RESULT_ERROR_ROLLBACK_INDEX for the slot in + * question. + * + * Note that androidboot.slot_suffix is not set in the |cmdline| field + * in |AvbSlotVerifyData| - you will have to pass this command-line + * option yourself. + * + * If a slot was selected and it verified then AVB_AB_FLOW_RESULT_OK + * is returned. + * + * If a slot was selected but it didn't verify then + * AVB_AB_FLOW_RESULT_OK_WITH_VERIFICATION_ERROR is returned. This can + * only happen when |allow_verification_error| is true. + * + * If an I/O operation - such as loading/saving metadata or checking + * rollback indexes - fail, the value AVB_AB_FLOW_RESULT_ERROR_IO is + * returned. + * + * If memory allocation fails, AVB_AB_FLOW_RESULT_ERROR_OOM is + * returned. + * + * Reasonable behavior for handling AVB_AB_FLOW_RESULT_ERROR_NO_BOOTABLE_SLOTS + * is to initiate device repair (which is device-dependent). + */ +AvbABFlowResult avb_ab_flow(AvbABOps* ab_ops, + const char* const* requested_partitions, + bool allow_verification_error, + AvbSlotVerifyData** out_data); + +/* Marks the slot with the given slot number as active. Returns + * AVB_IO_RESULT_OK on success, error code otherwise. + * + * This function is typically used by the OS updater when completing + * an update. It can also used by the firmware for implementing the + * "set_active" command. + */ +AvbIOResult avb_ab_mark_slot_active(AvbABOps* ab_ops, unsigned int slot_number); + +/* Marks the slot with the given slot number as unbootable. Returns + * AVB_IO_RESULT_OK on success, error code otherwise. + * + * This function is typically used by the OS updater before writing to + * a slot. + */ +AvbIOResult avb_ab_mark_slot_unbootable(AvbABOps* ab_ops, + unsigned int slot_number); + +/* Marks the slot with the given slot number as having booted + * successfully. Returns AVB_IO_RESULT_OK on success, error code + * otherwise. + * + * Calling this on an unbootable slot is an error - AVB_IO_RESULT_OK + * will be returned yet the function will have no side-effects. + * + * This function is typically used by the OS updater after having + * confirmed that the slot works as intended. + */ +AvbIOResult avb_ab_mark_slot_successful(AvbABOps* ab_ops, + unsigned int slot_number); + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_AB_FLOW_H_ */ diff --git a/libavb_ab/avb_ab_ops.h b/libavb_ab/avb_ab_ops.h new file mode 100644 index 0000000..8d8fde7 --- a/dev/null +++ b/libavb_ab/avb_ab_ops.h @@ -0,0 +1,79 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#if !defined(AVB_INSIDE_LIBAVB_AB_H) && !defined(AVB_COMPILATION) +#error \ + "Never include this file directly, include libavb_ab/libavb_ab.h instead." +#endif + +#ifndef AVB_AB_OPS_H_ +#define AVB_AB_OPS_H_ + +#include <libavb/libavb.h> + +#ifdef __cplusplus +extern "C" { +#endif + +struct AvbABOps; +typedef struct AvbABOps AvbABOps; + +struct AvbABData; + +/* High-level operations/functions/methods for A/B that are platform + * dependent. + */ +struct AvbABOps { + /* Operations from libavb. */ + AvbOps* ops; + + /* Reads A/B metadata from persistent storage. Returned data is + * properly byteswapped. Returns AVB_IO_RESULT_OK on success, error + * code otherwise. + * + * If the data read is invalid (e.g. wrong magic or CRC checksum + * failure), the metadata shoule be reset using avb_ab_data_init() + * and then written to persistent storage. + * + * Implementations will typically want to use avb_ab_data_read() + * here to use the 'misc' partition for persistent storage. + */ + AvbIOResult (*read_ab_metadata)(AvbABOps* ab_ops, struct AvbABData* data); + + /* Writes A/B metadata to persistent storage. This will byteswap and + * update the CRC as needed. Returns AVB_IO_RESULT_OK on success, + * error code otherwise. + * + * Implementations will typically want to use avb_ab_data_write() + * here to use the 'misc' partition for persistent storage. + */ + AvbIOResult (*write_ab_metadata)(AvbABOps* ab_ops, + const struct AvbABData* data); +}; + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_AB_OPS_H_ */ diff --git a/libavb_ab/libavb_ab.h b/libavb_ab/libavb_ab.h new file mode 100644 index 0000000..0dcf3e9 --- a/dev/null +++ b/libavb_ab/libavb_ab.h @@ -0,0 +1,40 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef LIBAVB_AB_H_ +#define LIBAVB_AB_H_ + +#include <libavb/libavb.h> + +/* The AVB_INSIDE_LIBAVB_AB_H preprocessor symbol is used to enforce + * library users to include only this file. All public interfaces, and + * only public interfaces, must be included here. + */ + +#define AVB_INSIDE_LIBAVB_AB_H +#include "avb_ab_flow.h" +#include "avb_ab_ops.h" +#undef AVB_INSIDE_LIBAVB_AB_H + +#endif /* LIBAVB_AB_H_ */ diff --git a/libavb_user/avb_ops_user.c b/libavb_user/avb_ops_user.c new file mode 100644 index 0000000..a95ce4d --- a/dev/null +++ b/libavb_user/avb_ops_user.c @@ -0,0 +1,253 @@ +/* + * Copyright (C) 2017 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include "avb_ops_user.h" + +#include <errno.h> +#include <fcntl.h> +#include <linux/fs.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include <cutils/properties.h> +#include <fs_mgr.h> + +#include <libavb_ab/libavb_ab.h> + +/* Open the appropriate fstab file and fallback to /fstab.device if + * that's what's being used. + */ +static struct fstab* open_fstab(void) { + struct fstab* fstab = fs_mgr_read_fstab_default(); + + if (fstab != NULL) { + return fstab; + } + + fstab = fs_mgr_read_fstab("/fstab.device"); + return fstab; +} + +static int open_partition(const char* name, int flags) { + char* path; + int fd; + struct fstab* fstab; + struct fstab_rec* record; + + /* We can't use fs_mgr to look up |name| because fstab doesn't list + * every slot partition (it uses the slotselect option to mask the + * suffix) and |slot| is expected to be of that form, e.g. boot_a. + * + * We can however assume that there's an entry for the /misc mount + * point and use that to get the device file for the misc + * partition. From there we'll assume that a by-name scheme is used + * so we can just replace the trailing "misc" by the given |name|, + * e.g. + * + * /dev/block/platform/soc.0/7824900.sdhci/by-name/misc -> + * /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a + * + * If needed, it's possible to relax this assumption in the future + * by trawling /sys/block looking for the appropriate sibling of + * misc and then finding an entry in /dev matching the sysfs entry. + */ + + fstab = open_fstab(); + if (fstab == NULL) { + return -1; + } + record = fs_mgr_get_entry_for_mount_point(fstab, "/misc"); + if (record == NULL) { + fs_mgr_free_fstab(fstab); + return -1; + } + if (strcmp(name, "misc") == 0) { + path = strdup(record->blk_device); + } else { + size_t trimmed_len, name_len; + const char* end_slash = strrchr(record->blk_device, '/'); + if (end_slash == NULL) { + fs_mgr_free_fstab(fstab); + return -1; + } + trimmed_len = end_slash - record->blk_device + 1; + name_len = strlen(name); + path = calloc(trimmed_len + name_len + 1, 1); + strncpy(path, record->blk_device, trimmed_len); + strncpy(path + trimmed_len, name, name_len); + } + fs_mgr_free_fstab(fstab); + + fd = open(path, flags); + free(path); + + return fd; +} + +static AvbIOResult read_from_partition(AvbOps* ops, + const char* partition, + int64_t offset, + size_t num_bytes, + void* buffer, + size_t* out_num_read) { + int fd; + off_t where; + ssize_t num_read; + AvbIOResult ret; + + fd = open_partition(partition, O_RDONLY); + if (fd == -1) { + ret = AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION; + goto out; + } + + if (offset < 0) { + uint64_t partition_size; + if (ioctl(fd, BLKGETSIZE64, &partition_size) != 0) { + avb_errorv( + "Error getting size of \"", partition, "\" partition.\n", NULL); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + offset = partition_size - (-offset); + } + + where = lseek(fd, offset, SEEK_SET); + if (where == -1) { + avb_error("Error seeking to offset.\n"); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + if (where != offset) { + avb_error("Error seeking to offset.\n"); + ret = AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION; + goto out; + } + + /* On Linux, we never get partial reads from block devices (except + * for EOF). + */ + num_read = read(fd, buffer, num_bytes); + if (num_read == -1) { + avb_error("Error reading data.\n"); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + if (out_num_read != NULL) { + *out_num_read = num_read; + } + + ret = AVB_IO_RESULT_OK; + +out: + if (fd != -1) { + if (close(fd) != 0) { + avb_error("Error closing file descriptor.\n"); + } + } + return ret; +} + +static AvbIOResult write_to_partition(AvbOps* ops, + const char* partition, + int64_t offset, + size_t num_bytes, + const void* buffer) { + int fd; + off_t where; + ssize_t num_written; + AvbIOResult ret; + + fd = open_partition(partition, O_WRONLY); + if (fd == -1) { + avb_errorv("Error opening \"", partition, "\" partition.\n", NULL); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + + where = lseek(fd, offset, SEEK_SET); + if (where == -1) { + avb_error("Error seeking to offset.\n"); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + if (where != offset) { + avb_error("Error seeking to offset.\n"); + ret = AVB_IO_RESULT_ERROR_RANGE_OUTSIDE_PARTITION; + goto out; + } + + /* On Linux, we never get partial writes on block devices. */ + num_written = write(fd, buffer, num_bytes); + if (num_written == -1) { + avb_error("Error writing data.\n"); + ret = AVB_IO_RESULT_ERROR_IO; + goto out; + } + + ret = AVB_IO_RESULT_OK; + +out: + if (fd != -1) { + if (close(fd) != 0) { + avb_error("Error closing file descriptor.\n"); + } + } + return ret; +} + +AvbOps* avb_ops_user_new(void) { + AvbOps* ops; + + ops = calloc(1, sizeof(AvbOps)); + if (ops == NULL) { + avb_error("Error allocating memory for AvbOps.\n"); + goto out; + } + + ops->ab_ops = calloc(1, sizeof(AvbABOps)); + if (ops->ab_ops == NULL) { + avb_error("Error allocating memory for AvbABOps.\n"); + free(ops); + goto out; + } + ops->ab_ops->ops = ops; + + ops->read_from_partition = read_from_partition; + ops->write_to_partition = write_to_partition; + ops->ab_ops->read_ab_metadata = avb_ab_data_read; + ops->ab_ops->write_ab_metadata = avb_ab_data_write; + +out: + return ops; +} + +void avb_ops_user_free(AvbOps* ops) { + free(ops->ab_ops); + free(ops); +} diff --git a/libavb_user/avb_ops_user.h b/libavb_user/avb_ops_user.h new file mode 100644 index 0000000..4e547b9 --- a/dev/null +++ b/libavb_user/avb_ops_user.h @@ -0,0 +1,48 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef AVB_OPS_USER_H_ +#define AVB_OPS_USER_H_ + +#include <libavb/libavb.h> + +#ifdef __cplusplus +extern "C" { +#endif + +/* Allocates an AvbOps instance suitable for use in userspace on the + * device. Returns NULL on OOM. + * + * Free with avb_ops_user_free(). + */ +AvbOps* avb_ops_user_new(void); + +/* Frees an AvbOps instance previously allocated with avb_ops_device_new(). */ +void avb_ops_user_free(AvbOps* ops); + +#ifdef __cplusplus +} +#endif + +#endif /* AVB_OPS_USER_H_ */ diff --git a/libavb_user/libavb_user.h b/libavb_user/libavb_user.h new file mode 100644 index 0000000..4b34bdd --- a/dev/null +++ b/libavb_user/libavb_user.h @@ -0,0 +1,39 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef LIBAVB_USER_H_ +#define LIBAVB_USER_H_ + +#include <libavb_ab/libavb_ab.h> + +/* The AVB_INSIDE_LIBAVB_USER_H preprocessor symbol is used to enforce + * library users to include only this file. All public interfaces, and + * only public interfaces, must be included here. + */ + +#define AVB_INSIDE_LIBAVB_USER_H +#include "avb_ops_user.h" +#undef AVB_INSIDE_LIBAVB_USER_H + +#endif /* LIBAVB_USER_H_ */ diff --git a/tools/avbctl/avbctl.cc b/tools/avbctl/avbctl.cc new file mode 100644 index 0000000..0842c59 --- a/dev/null +++ b/tools/avbctl/avbctl.cc @@ -0,0 +1,255 @@ +/* + * Copyright (C) 2017 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#include <stdio.h> +#include <string.h> +#include <sysexits.h> + +#include <android/hardware/boot/1.0/IBootControl.h> + +#include <libavb_user/libavb_user.h> + +using android::sp; +using android::hardware::hidl_string; +using android::hardware::Return; +using android::hardware::boot::V1_0::IBootControl; +using android::hardware::boot::V1_0::Slot; + +namespace { + +/* Prints program usage to |where|. */ +void usage(FILE* where, int /* argc */, char* argv[]) { + fprintf(where, + "%s - command-line tool for AVB.\n" + "\n" + "Usage:\n" + " %s COMMAND\n" + "\n" + "Commands:\n" + " %s disable-verity - Disable verity in current slot.\n" + " %s enable-verity - Enable verity in current slot.\n", + argv[0], + argv[0], + argv[0], + argv[0]); +} + +/* Returns the A/B suffix the device booted from or the empty string + * if A/B is not in use. + */ +std::string get_ab_suffix(sp<IBootControl> module) { + std::string suffix = ""; + + if (module != nullptr) { + uint32_t num_slots = module->getNumberSlots(); + if (num_slots > 1) { + Slot cur_slot = module->getCurrentSlot(); + Return<void> ret = + module->getSuffix(cur_slot, [&suffix](const hidl_string& value) { + suffix = std::string(value.c_str()); + }); + if (!ret.isOk()) { + fprintf(stderr, "Error getting suffix for slot %d.\n", cur_slot); + } + } + } + + return suffix; +} + +/* Loads the toplevel AvbVBMetaImageHeader from the slot denoted by + * |ab_suffix| into |vbmeta_image|. No validation, verification, or + * byteswapping is performed. + * + * If successful, |true| is returned and the partition it was loaded + * from is returned in |out_partition_name| and the offset on said + * partition is returned in |out_vbmeta_offset|. + */ +bool load_top_level_vbmeta_header( + AvbOps* ops, + const std::string& ab_suffix, + uint8_t vbmeta_image[AVB_VBMETA_IMAGE_HEADER_SIZE], + std::string* out_partition_name, + uint64_t* out_vbmeta_offset) { + std::string partition_name = std::string("vbmeta") + ab_suffix; + uint64_t vbmeta_offset = 0; + + // Only read the header. + size_t num_read; + AvbIOResult io_res = ops->read_from_partition(ops, + partition_name.c_str(), + vbmeta_offset, + AVB_VBMETA_IMAGE_HEADER_SIZE, + vbmeta_image, + &num_read); + if (io_res == AVB_IO_RESULT_ERROR_NO_SUCH_PARTITION) { + AvbFooter footer; + // Try looking for the vbmeta struct in 'boot' via the footer. + partition_name = std::string("boot") + ab_suffix; + io_res = ops->read_from_partition(ops, + partition_name.c_str(), + -AVB_FOOTER_SIZE, + AVB_FOOTER_SIZE, + &footer, + &num_read); + if (io_res != AVB_IO_RESULT_OK) { + fprintf(stderr, + "Error loading footer from partition '%s' (%d).\n", + partition_name.c_str(), + io_res); + return false; + } + + if (memcmp(footer.magic, AVB_FOOTER_MAGIC, AVB_FOOTER_MAGIC_LEN) != 0) { + fprintf(stderr, + "Data from '%s' does not look like a vbmeta footer.\n", + partition_name.c_str()); + return false; + } + + vbmeta_offset = avb_be64toh(footer.vbmeta_offset); + io_res = ops->read_from_partition(ops, + partition_name.c_str(), + vbmeta_offset, + AVB_VBMETA_IMAGE_HEADER_SIZE, + vbmeta_image, + &num_read); + } + + if (io_res != AVB_IO_RESULT_OK) { + fprintf(stderr, + "Error loading from offset %" PRIu64 " of partition '%s' (%d).\n", + vbmeta_offset, + partition_name.c_str(), + io_res); + return false; + } + + if (out_partition_name != nullptr) { + *out_partition_name = partition_name; + } + if (out_vbmeta_offset != nullptr) { + *out_vbmeta_offset = vbmeta_offset; + } + return true; +} + +/* Function to enable and disable dm-verity. The |ops| parameter + * should be an |AvbOps| from libavb_user and |module| can either be + * |nullptr| or a valid boot_control module. + */ +int do_set_verity(AvbOps* ops, sp<IBootControl> module, bool enable_verity) { + uint8_t vbmeta_image[AVB_VBMETA_IMAGE_HEADER_SIZE]; // 256 bytes. + std::string ab_suffix; + std::string partition_name; + uint64_t vbmeta_offset; + AvbIOResult io_res; + + ab_suffix = get_ab_suffix(module); + + if (!load_top_level_vbmeta_header( + ops, ab_suffix, vbmeta_image, &partition_name, &vbmeta_offset)) { + return EX_SOFTWARE; + } + + if (memcmp(vbmeta_image, AVB_MAGIC, AVB_MAGIC_LEN) != 0) { + fprintf(stderr, + "Data from '%s' does not look like a vbmeta header.\n", + partition_name.c_str()); + return EX_SOFTWARE; + } + + // Set/clear the HASHTREE_DISABLED bit, as requested. + AvbVBMetaImageHeader* header = + reinterpret_cast<AvbVBMetaImageHeader*>(vbmeta_image); + uint32_t flags = avb_be32toh(header->flags); + flags &= ~AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED; + if (!enable_verity) { + flags |= AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED; + } + header->flags = avb_htobe32(flags); + + // Write the header. + io_res = ops->write_to_partition(ops, + partition_name.c_str(), + vbmeta_offset, + AVB_VBMETA_IMAGE_HEADER_SIZE, + vbmeta_image); + if (io_res != AVB_IO_RESULT_OK) { + fprintf(stderr, + "Error writing to offset %" PRIu64 " of partition '%s' (%d).\n", + vbmeta_offset, + partition_name.c_str(), + io_res); + return EX_SOFTWARE; + } + + fprintf(stdout, + "Successfully %s verity on %s.\n", + enable_verity ? "enabled" : "disabled", + partition_name.c_str()); + + return EX_OK; +} + +} // namespace + +int main(int argc, char* argv[]) { + int ret; + sp<IBootControl> module; + AvbOps* ops = nullptr; + + if (argc < 2) { + usage(stderr, argc, argv); + ret = EX_USAGE; + goto out; + } + + ops = avb_ops_user_new(); + if (ops == nullptr) { + fprintf(stderr, "Error getting AVB ops.\n"); + ret = EX_SOFTWARE; + goto out; + } + + // Failing to get the boot_control HAL is not a fatal error - it can + // happen if A/B is not in use, in which case |nullptr| is returned. + module = IBootControl::getService(); + + if (strcmp(argv[1], "disable-verity") == 0) { + ret = do_set_verity(ops, module, false); + } else if (strcmp(argv[1], "enable-verity") == 0) { + ret = do_set_verity(ops, module, true); + } else { + usage(stderr, argc, argv); + ret = EX_USAGE; + } + + ret = EX_OK; +out: + if (ops != nullptr) { + avb_ops_user_free(ops); + } + return ret; +} |